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[structural similarities between the hypocalcemia hormone of the corpuscles of stannius of the eel (anguilla anguilla l.) and the mammalian parathyroid hormone].extracts of the corpuscules of stannius enhance eel gill calcium efflux and increase bone resorption in the rat. thus the hormone is hypocalcaemic in the eel although hypercalcaemic in the rat. we show here that a 15 min. pulse perfusion of a synthetic fragment of human pth 1-34 had a similar effect on gill calcium fluxes to that of cs extract. further, we found that eel plasma contains a substance reacting with five different antibodies against bovine pth. the concentration of this plasma mater ...19806784952
galanin-like immunoreactivity in the brain of teleosts: distribution and relation to substance p, vasotocin, and isotocin in the atlantic salmon (salmo salar).the presence of galanin-like substances and their relation to substance p-, vasotocin-, and isotocin-immunoreactive neurons and fibers in the brain of teleosts was investigated with immunohistochemical methods. two specific antisera against synthetic porcine galanin (gal) revealed cell bodies and fibers in the brain of four different teleost species (salmo salar, carassius carassius, gasterosteus aculeatus, and anguilla anguilla). in all four species the main location of galanin immunoreactivity ...19801713923
acute responses of the freshwater eel (anguilla anguilla) to extracts of the corpuscles of stannius opposing the effects of stanniosomatiectomy. 19807409455
paradoxical effect of 1,25 dihydroxycholecalciferol on osteoblastic and osteoclastic activity in the skeleton of the eel anguilla anguilla l.female mature eels (300 to 500 g) received one intraperitoneal injection of 1.25(oh)2d3 (10 microgram). their vertebral bone was compared, 8 h and 24 h after the injection, with vertebral bone of control mature female eels receiving solvent alone (ethanol). sexual maturation in female eels induces a bone decalcification with hypercalcaemia and hyperphosphataemia. the control eels showed marked osteoclastic resorption and osteocytic osteolysis and the degree of mineralization of the intercellular ...19806775784
the uptake from fresh water and subsequent clearance of a vanadium burden by the common eel (anguilla anguilla).the uptake of 48v vanadium from a solution of 10(-5) m 48v-orthovanadate by fresh-water elvers and the subsequent depletion of the vanadium burden was studied. at the end of the 8-week loading period, the levels of 48v were still increasing in the liver, kidney, bone and carcase. the uptake rate for the whole fish over the 8-week period was 760 pg atom/h/100 g body wt and the depletion rate over the following 5 weeks in clean water was about one tenth of this. liver contained the highest amount ...19817280655
effects of orthovanadate on salt and water effluxes from the gills of seawater eels, anguilla anguilla.orthovanadate (5 . 10(-7) m) perfused through isolated gills at a constant rate increased the perfusion pressure by 40% but inhibited the effluxes of na+ and cl- by 40%. water efflux was unaltered. ouabain (10(-4) m) and rotenone (10(-4) m) influenced salt and water effluxes in the same way but did not alter perfusion pressures. orthovanadate (10(-5) m) perfused at constant rate increased the pressure nearly 2.5-fold; under these conditions effluxes of na+, cl- and h2o were all increased approxi ...19816911027
differences in concentrations of plasma cortisol in the trout and the eel following adaptation to black or white backgrounds.when rainbow trout (salmo gairdneri) and eels (anguilla anguilla) were kept in black tanks for 3-4 weeks, their plasma cortisol titres were about fourfold higher tha in fish kept in white tanks. in trout, the difference was apparent only under a long photoperiod of 16 h light: 8 h darkness, but in eels the difference was clear under both a long or short photoperiod (9.5 h light: 14.5 darkness). it is suggested that the increase in plasma cortisol seen in black-adapted fish is dependent on either ...19817217835
comparative studies on the chromosomes of the european eel (anguilla anguilla l.) and the american eel (anguilla rostrata le sueur). 19817238951
histochemical and ultrastructural study of the nervous elements in the pineal organ of the eel, anuilla anguilla.the pineal organ of the eel, anguilla anguilla was studied light-and electron-microscopically. the tissue consists predominantly of glia-like supporting cells and photoreceptor-like sensory cells, which establish synaptic contacts with pineal nerve cells. histochemically, a positive acetylcholinesterase (ache) reaction can be observed in the perinuclear cytoplasm of the nerve cells and in the inner segments of the photoreceptor cells. based on the intensity of the ache reaction and the dimension ...19817237520
cl- -hco3- dependent atpase in gills of freshwater and seawater adapted eels (anguilla anguilla l.).the gills of both seawater and freshwater adapted eels have an atpase activity which is stimulated by anions in the presence of mg2+. plasma membranes were distinguished from mitochondrial membranes with specific enzyme markers, the membrane fractions separated on a discontinuous sucrose gradient, and the atpase activity of the plasma membranes studied. activation by the anions of cl- or hco3- followed michaelis-menten kinetics and was competitively inhibited by scn-. the cl- and hco3- activatio ...19816260235
distribution of c-band heterochromatin in the zw sex chromosomes of european and american eels (anguillidae, teleostomi).the zw sex chromosomes of the european eel, anguilla anguilla, and the american eel, a. rostrata, were examined with c-band and fluorescent staining to demonstrate the c-band heterochromatin. the w as well as z chromosomes in both species are c-band negative except for a small amount of c-band heterochromatin in the centromeric region, in contrast to the w or y elements of most other vertebrates. no fluorescing w-associated body is evident either in interphase nuclei or in metaphase plates. the ...19816173168
effect of stress on the circadian rhythmicity of hypothalamic catecholamine content in the eel (anguilla anguilla l.). 19816117406
blood-brain barrier for serotonin in the eel (anguilla anguilla l.). 19816112113
[immunocytochemical detection in stannius corpuscles of the eel (anguilla anguilla l.) of a hormone similar to the mammalian parathyroid hormone].in eels the parathyrin of the corpuscles of stannius (pcs), mammalian parathyroid-like hormone, has been localized in the cytoplasm of all the cells in the corpuscles. this detection was done by indirect immunofluorescence with an antiserum anti 1-84 bovine parathormone. the specificity of the reaction was demonstrated by inhibition of the coloration obtained with the 1-84 bovine parathormone and the active fragment 1-34 of human parathormone. variations of the cellular localization of the pcs o ...19816802446
[effect of change of habitat (sea and fresh water) on in vivo thyroglobulin synthesis in atlantic glassed eels (anguilla anguilla l.)].thyroid biosynthesis in glassed eels (anguilla anguilla l.) was studied to establish whether salinity changes could affect it, when they live in sea water or in fresh water containing 125i. aqueous extrait of homogenized cephalic heads of glassed eels contains an iodinated protein 17-19 s having thyroglobulin-like properties and including iodotyrosins (mit and dit) and thyroid hormones (3 and t4). biosynthesis of this proteins is roughly twice more important in fresh water than in sea water at 1 ...19816457669
[appearance of anguillicola australiensis johnston and mawson, 1940 (dracuncoloidea: anguillicolidae) in anguilla anguilla of lake bracciano].anguillicola australiensis johnston and mawson, 1940 is redescribed and reported for the first time from anguilla anguilla of lake bracciano (rome-italy). it is suggested that the appearance of anguillicola australiensis in european eels might be in relation with intercontinental live eels transfers.19826926929
serological cross-reactivity to rat anti h-y antiserum in the female european eel (anguilla anguilla). 19827106453
habitat specificity of the acanthocephalan acanthocephalus clavula (dujardin, 1845) in eels anguilla anguilla (l).the habitat specificity of the acanthocephalan acanthocephalus clavula in the alimentary tract of eels was studied in natural infections and in fish maintained experimentally under different regimes. the parasite exhibited a preference for a particular region (55 to 65%) of the alimentary canal which did not differ in different species of host, but habitat specificity was not very precise as there was considerable variation between individual hosts and a. calvula was capable of surviving and mat ...19827096967
elevated sister chromatid exchange rate in lymphocytes of the european eel (anguilla anguilla) with cauliflower tumor.sister chromatid exchange (sce) frequency and chromosomal aberration were studied in cultured lymphocytes from the european eel (anguilla anguilla) with cauliflower tumors. sce was significantly increased in the affected fishes compared with normal controls, whereas chromosomal aberration did not. in comparison to normal cells, the lymphocytes responding to phytohemagglutinin m (pha-m) in cultures from tumorous eels showed no evidence of cell cycle retardation. a possible mechanism for elevation ...19827066876
retinofugal projections in the eel, anguilla anguilla l. (teleostei), visualized by the cobalt-filling technique.the retinofugal projections in the eel were studied by use of the cobalt-filling technique. the optic tract projects contralaterally to the hypothalamic optic nucleus, the anterior periventricular nucleus, the lateral geniculate nucleus, the dorsomedial optic nucleus, four pretectal recipient areas, the optic tectum, and the tegmentum. small ipsilateral projections were demonstrated in the hypothalamic optic nucleus, the dorsomedial optic nucleus, and the optic tectum.19826181888
effects of anaesthesia and surgery on levels of adrenaline and noradrenaline in blood plasma of the eel (anguilla anguilla l.).1. the effects of surgery and anaesthesia on adrenaline and noradrenaline plasma levels were investigated in the eel (anguilla anguilla l.). 2. effect of surgery: highest values were obtained when putting back the fish in water. three hours after surgery, adrenaline and noradrenaline plasma levels were always significantly higher than those obtained 24 and 48 hr after surgery. 3. effect of anaesthesia: anaesthesia only had no effect on adrenaline and noradrenaline plasma levels. 4. it was conclu ...19826125328
a morphometric analysis of regional differences in myotomal muscle ultrastructure in the juvenile eel (anguilla anguilla l.).subpopulations of fast and slow fibres within the trunk musculature of elvers were examined using morphometric analysis of electron micrographs. fibre regions were characterised by their histochemical staining characteristics, and individual fibres located using a coordinate mapping system utilising morphological features as reference points. percentages of fibre volume occupied by mitochondria, myofibrils, sarcoplasmic reticulum (s.r.), and t-system were determined in each of the fibre groups, ...19827060104
muscle fibre differentiation and vascularisation in the juvenile european eel (anguilla anguilla l.).the differentiation of the lateral musculature in the elver stage of the european eel (anguilla anguilla, l.) has been studied using histochemical staining techniques. extracellular lipid deposits constitute 12% of the body cross-sectional area. two fibre type may be distinguished on the basis of myofibrillar atpase activity. fibres with an alkaline-labile (ph 10.2) atpase occur as a two-fibre layer around the trunk circumference, with invaginations along the horizontal septum and fin insertions ...19826277491
presence and distribution of radioimmunoassayable lhrh in the european eel, anguilla anguilla.eel brain contains a factor which exhibited a complete cross-reaction in a radioimmunoassay (ria) for mammalian luteinizing hormone-releasing hormone (lhrh) and which exhibited a behavior similar to that of synthetic mammalian lhrh on sephadex g-25. eel brains contained 920 +/- 135 pg of this lhrh-like immunoreactive factor (ir-lhrh); 75% of immunoreactivity was present in the di- and mes-encephalon, 21% in the telencephalon and 4% in the hind-brain. thus, ir-lhrh in eel brain exhibited a much w ...19826761597
two different anti-galactan lectins in eel serum.two different anti-galactan lectins from eel serum (anguilla anguilla) were isolated by affinity chromatography on fucogel and on 1-acyl-2-(9-carboxy)nonyl-glycero-3-phosphocholine coupled to aminohexyl-sepharose. the fucolectin and the crp-analogue protein thus purified directly from the eel serum were characterized by sds-gradient gel electrophoresis, immunoelectrophoresis, and by agar gel diffusion tests. the crp-analogue protein with a molecular weight of 24.800 daltons was present in a high ...19827173977
diurnal variation of 5-hydroxytryptamine content in the pineal organ of the yellow eel (anguilla anguilla (l.)). 19827200045
steroid production in testicular tissue of the european eel.testicular tissue of normal and hcg-stimulated european eels was incubated in vitro with tritiated progesterone or androstenedione as substrates. the following compounds were isolated and identified: 5 beta-androstane-3,17-dione; 17 beta-hydroxy-5 beta-androstan-3-one; androst-4-ene-3,11,17-trione (adrenosterone); 11 beta-hydroxyandrost-4-ene-3,17-dione; 11 beta-hydroxytestosterone; 3 alpha,11 beta-dihydroxy-5 beta-androstan-17-one, and an additional steroid for which the oxidation product was i ...19827035150
retinal fine structure in the european eel anguilla anguilla. i. pigment epithelium of the glass eel stage.the european eel (anguilla anguilla) has a complex life cycle during which it changes habitat and to some extent morphology. during this time the eye undergoes modifications in both size and photopigments. this report forms the first of a comparative morphological study of the retina of the eel during the major stages of its life cycle. the retinal pigment epithelium of the glass eel stage consists of a single layer of cuboidal cells joined laterally by cell junctions. both the basal (scleral) a ...19827103098
the parapineal and pineal organs of the elver (glass eel), anguilla anguilla l.the parapineal organ of the glass eel (elver) consists of approximately 400 cells and is situated to the left of the connection of the pineal stalk to their ventricle. a conspicuous nerve tract containing approximately 350 fibers arises from the parapineal organ and runs in spatial relationship to the habenular commissure toward the left habenular nucleus. the dominating cell type of the parapineal organ of the elver is a neuron (sensory neuron) of small diameter provided with atypical cilia (9 ...19827083311
development of a heterologous radioimmunoassay for eel (anguilla anguilla) gonadotropin.a heterologous radioimmunoassay (ria) for eel gonadotropin (gth) was developed, using an antiserum to the beta subunit of carp gth (cgthbeta). partially purified eel gth preparations or crude eel pituitary extracts produced partial cross-reactions: the inhibition curves reached a plateau before complete inhibition of the binding of the tracer and the slopes were lower than those for cgth. however, the parallelism between the inhibition curves produced by all the eel samples allowed estimation of ...19836301935
response of prolactin cells to environmental calcium in the eel (anguilla anguilla l.).prolactin (prl) cell activity was investigated in eels kept in fresh water (fw), deionized water (dw) supplemented or not with ca (2 mm), in ca-enriched fw (10 mm), in normal (ca 3.4 mm) or ca-free 1/3 sea water (sw), and in sw (ca 10.2 mm) or ca-free sw (ca 0.15 mm). light-microscopic studies, including measurement of the nuclear area and cell height, showed that prl cell activity, reduced in dw, is not affected by ca supplementation. activity is reduced in ca-enriched fw, in 1/3 sw and in sw, ...19836850745
seasonal variations in circadian rhythm of hypothalamic catecholamine content in the eel (anguilla anguilla l.).1. changes in catecholamine content (ca) in hypothalamus of male and female eel (anguilla anguilla l.) were defined using the falck-hillarp histochemical fluorescence method for a 24-hr period during the summer (l:d = 16:8) and winter (l:d = 8:16). 2. a circadian rhythm in the catecholamine content was found in the hypothalamus. ca content was lower by night than by day. 3. a longer light day (summer period) caused the shifting of rhythm phase in ca content. 4. sex of eels does not affect ca con ...19836135557
the transport of orthovanadate and similar oxyanions in relation to salt and water transport across the isolated intestine of the common eel, anguilla anguilla.an intestinal preparation from the common eel (anguilla anguilla) was characterized for both mucosal to serosal and serosal to mucosal transport of water, alanine, sodium and chloride. the preparation showed a net outflux of water and a net influx of alanine, and no net fluxes of sodium or chloride. the influxes of all four substances and the outflux of water were inhibited by ouabain, while the outfluxes of alanine, sodium and chloride were increased by ouabain. influxes and outfluxes of the ox ...19836550622
[effect of salmon calcitonin on intestinal absorption of calcium in the eel (anguilla anguilla l.)].salmon calcitonin (sct) acted, in eel, on ca intestinal absorption by modulating ca flux lumen-plasma (phi calp) intensity. this response was dependent upon the basal value of the intestinal ca absorption; a linear relation between the basal phi calp and its variation after sct was shown. after stannius corpuscles removal the lower phi calp was stimulated by sct in all cases.19836416625
opsin-immunoreactive outer segments in the pineal and parapineal organs of the lamprey (lampetra fluviatilis), the eel (anguilla anguilla), and the rainbow trout (salmo gairdneri).the pineal complex of lampetra fluviatilis, anguilla anguilla and salmo gairdneri was studied by means of the indirect immunohistochemical antiopsin reaction. opsin-immunoreactive material was demonstrated in the outer segments of the photoreceptor cells in the pineal organ of all three species investigated. in the lamprey, the opsin-positive outer segments were located in the lumen of the pineal vesicle and atrium. in the two teleost species, the immunoreactive outer segments were observed in a ...19836221801
vasoconstrictory effects of adrenalin on the perfused head of the eel (anguilla anguilla l.).adrenalin (5.0 x 10(-5) m) increases gill vascular resistance up to 23.2 +/- 6.8% in the isolated and perfused head of the european eel (anguilla anguilla l.). this vasoactive response is nearly abolished by the alpha-adrenergic blocking agent phentolamine mesylate (5.0 x 10(-5) m), while it is increased by the beta-blocker propranolol (5.0 x 10(-4) m). from these results it may be inferred that, in our experimental conditions, the major response to the catecholamine is a vasoconstriction mediat ...19836139251
separation by velocity sedimentation of the gill epithelial cells and their atpases activities in the seawater adapted eel anguilla anguilla l.the separation of cell populations by sedimentation was carried out on heterogeneous suspensions of branchial cells of the seawater adapted eel anguilla anguilla. the cell sedimentation rates vary mainly in relation to size and permit the separation of enriched fractions of chloride cells and respiratory cells. the method is described and discussed. the homogeneity of the separated populations was checked by microscopy and particle counting. an enrichment of 95% by volume concentration of the tw ...19836137310
csf-contacting and other somatostatin-immunoreactive neurons in the brains of anguilla anguilla, phoxinus phoxinus, and salmo gairdneri (teleostei).a system of somatostatin-immunoreactive neurons was demonstrated in the brains of the eel, anguilla anguilla, the european minnow, phoxinus phoxinus, and the rainbow trout, salmo gairdneri, by means of the light-microscopic indirect immunoperoxidase technique. in the anterior periventricular nucleus, somatostatin-immunoreactive cerebrospinal fluid (csf)-contacting neurons display intensely stained intraventricular dendritic protrusions, perikarya, and axonal processes. the latter taper into a so ...19836137283
sex determination in the european eel (anguilla anguilla, l.). a hypothesis based on cytogenetic results, correlated with the findings of skewed sex ratios in eel culture ponds.metaphase chromosomes from cultured blood cells of female, male, and hermaphroditic european eels were analyzed. in addition, both gonads from each of the specimens were examined microscopically to ensure correct sexing. the karyological investigation revealed that in some of the specimens a heteromorphic chromosome pair was present. this heteromorphism appeared in both sexes and in the hermaphrodite. c-banding and silver nitrate staining demonstrated that the heteromorphism was due to quantitat ...19836661926
influence of temperature, environmental salinity and fasting on the patterns of fatty acids synthesized by gills and liver of the european eel (anguilla anguilla).a rise in temperature on the average from 8 to 28 degrees c resulted in an enhanced relative incorporation of [1-14c]acetate into saturated fatty acids in liver tissue. the same effect was seen in gill tissue, but only after incubation in vitro and when the precursor was injected into the eel. when [1-14c]acetate was added to the water in the incubation tank such a "homeoviscous adaption" was not observed in gill tissue. a rise in temperature resulted in less relative incorporation of radioactiv ...19836617156
structure and motility of the 9 + 0 flagellum of eel spermatozoa.scanning and electron microscopic study of the spermatozoon of the eel, anguilla anguilla, has shown that the large oblong head is attached eccentrically by one end to the basal end of the true flagellum and contains a pseudoflagellum that splits into two groups of tubules as it passes around the nucleus. the 9+0 axoneme of the true flagellum lacks outer dynein arms and the radial spoke complex. the movement of anguilla sperm is characterized by rapid forward progression that is the result of le ...19836842644
effects of steroid hormones on pituitary immunoreactive gonadotropin in european freshwater eel, anguilla anguilla l.the low pituitary immunoreactive gonadotropin (ir gth) contents of immature female or male freshwater eels were strongly increased after intraperitoneal injections of estradiol. using female eels, the effect was shown to be dose dependent. in neither sex was modification of pituitary ir gth observed after progesterone treatment; a very small increase (significant in females but not in males) was produced by cortisol. an important sexual difference occurred with testosterone, which strongly stimu ...19836654031
depression of sodium, chloride and calcium ions in the plasma of goldfish (carassius auratus) and immature freshwater- and seawater-adapted eels (anguilla anguilla l.) after acute administration of salmon calcitonin.goldfish showed a significant reduction in their plasma sodium and calcium levels 1 h after receiving 50 i.u. calcitonin per kg body weight. when 100 i.u. calcitonin were injected there was a significant fall in circulating levels of both sodium and calcium and also of chloride ions compared with those found in untreated control animals. administration of calcitonin to immature eels adapted to either freshwater or seawater conditions showed no significant change in plasma ion composition at dose ...19836875432
root effect induced by co2 and by fixed acid in the blood of the eel, anguilla anguilla.the decrease in o2 capacity with decreasing ph (root effect) was studied in eel blood in which ph was varied in the range 5 to 9 both by addition of acid or base (fixed-acid root effect) and by varying pco2 (co2 root effect). hemoglobin-bound oxygen was independent of po2 above 150 torr and was thus referred to as o2 capacity (o2cap). at ph below 8.5, o2cap decreased sigmoidally with ph to attain, below a ph of 6.0, a value which, at 15 degrees c, averaged about 48% of the maximum o2cap, measure ...19836405470
effects of adrenaline on isolated heart of the eel (anguilla anguilla l.) during winter.1. the intrinsic effects of adrenaline on the myocardium of the eel in winter were investigated in the isolated perfused eel heart. 2. adrenaline was ineffective both on the pacemaker activity and auricular action potentials but markedly increased ventricular action potential duration, thus leading to an auriculo-ventricular desynchronisation. 3. this effect was not reversed by propranolol but was by phentolamine and was attributed to the stimulation of alpha receptors. 4. clonidine reproduced t ...19836133696
an investigation of the carbonic anhydrase inhibitor in eel plasma.1. carbonic anhydrase activity in blood and gill from freshwater and seawater acclimated european eels, anguilla anguilla has been determined. 2. plasma from freshwater and seawater eels possess a potent inhibitor of erythrocytic carbonic anhydrase, in agreement with previous investigations on freshwater fish. 3. the plasma inhibitor is equally effective against gill and gut carbonic anhydrase from the eel. although not as potent, the eel inhibitor is also effective against ca from rainbow trout ...19836130879
[stimulation of peripheral conversion of thyroxine to triiodothyronine by ovine somatotropic hormone in the eel (anguilla anguilla l.)].one injection of ovine growth hormone (1.27 x 10(-5) usp units/g body weight) determines in the eel, 1 day later, a twofold decrease in plasma thyroxine level as well as a twofold increase in plasma triiodothyronine level. these modifications of circulating iodothyronine levels result from a considerable stimulation of the peripheral deiodination of thyroxine to triiodothyronine, shown by a kinetic study of labelled thyroxine metabolism. the increase of production of metabolically active hormone ...19836405997
effects of temperature and dose level on in vivo dynamics of unlabelled bovine insulin in eels (anguilla anguilla l.).the in vivo dynamics of bolus-injected, unlabelled bovine insulin in eels (anguilla anguilla l.), analysed by compartmental and noncompartmental methods, were found to be significantly influenced by acclimation temperature and insulin dose level. at 12 degrees, plasma clearance of insulin was essentially monoexponential, whereas at 22 degrees, the disappearance curves could be resolved into two exponential components. metabolic clearance rate (mcr) and apparent distribution volume (vdist) of ins ...19836341164
immunocytochemistry of gonadotropic cells in the pituitary of some teleost species.an antiserum (anti-sgth) raised against salmon gonadotropin (sg-g100) was tested on pituitary sections of sarotherodon mossambicus, carassius auratus, anguilla anguilla (intact and estradiol-treated to induce the development of the gonadotropic (gth) cells), salmo trutta fario, and a protandric marine teleost (sarpa salpa, sparidae). using an immunoenzymologic technique, anti-sgth stained gth and thyrotropic (tsh) cells in the species studied. anti-sgth stained the granulated gth cells in s. tru ...19836862173
retinal fine structure in the european eel anguilla anguilla. iii. pigment epithelium of the yellow eel stage.the catadromous migrations of the european eel (anguilla anguilla) are accompanied by a number of morphological and biochemical alterations within the visual system. this report describes the morphology of the retinal pigment epithelium, choriocapillaris and bruch's membrane of the yellow eel and forms the third in a series describing the morphological changes in the retina of the eel during its life cycle. the retinal epithelium of the yellow eel stage consists of a single layer of cuboidal cel ...19846529011
retinal fine structure in the european eel anguilla anguilla. ii. photoreceptors of the glass eel stage.the eye of the european eel (anguilla anguilla) undergoes marked morphological changes during its long and complex life cycle. this report describes the fine structure of the photoreceptors of the glass eel stage and forms part of a comparative study of the retina of the eel during the major stages of its life cycle. the photoreceptors of the glass eels are readily divisible into rods and cones based on morphological criteria. rods are more numerous and much longer than cone cells, reaching to t ...19846507891
the effect of prolonged fasting on total lipid synthesis and enzyme activities in the liver of the european eel (anguilla anguilla).the extent of fatty acid synthesis from [1-14c]acetate in liver slices was reduced 6-fold when eels were fasted for 1-7 weeks and 20-fold when fasted for 39 weeks; thereafter hepatic lipogenesis seemed to remain constant for up to 95 weeks of fasting. after a 1-3 week fast some hepatic enzyme activities were reduced (acetyl-coa carboxylase decreased 2-fold and fatty acid synthetase declined 5-fold), while others remained unchanged (glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogen ...19846150805
circadian variations of catecholamine levels in brain, heart, and plasma in the eel, anguilla anguilla l., at three different times of year.the amounts of catecholamine (dopamine, adrenaline, and noradrenaline) in the brain, heart, and plasma of the eel (anguilla anguilla l.) during a 24-hr period and at three different times of year were determined by using a radioenzymatic method. seasonal variations of catecholamine average values were found to be different when considering catecholamine levels in the same tissue (one exception: heart levels in may) or the same amine in different tissues. circadian rhythms of catecholamine levels ...19846468922
physicochemical properties and n-terminal sequence of eel lectin.some physicochemical properties of the l-fucose-binding lectin from the serum of the european eel (anguilla anguilla) were determined. the lectin is a dimer composed of identical subunits of mr approx. 40000. in agreement with previous results [horejsí & kocourek (1978) biochim. biophys. acta 538, 299-315], the subunit was shown to comprise two non-glycosylated polypeptides of mr approx. 20000 and linked by disulphide bonds. n-terminal sequence analysis, carboxypeptidase digestion and peptide ma ...19846743262
influence of thermal acclimation on glucose production and ketogenesis in isolated eel hepatocytes.hepatocytes were isolated by collagenase perfusion of the liver from adult eels (anguilla anguilla l.) acclimated to different temperatures. whereas the relative weight of the liver increased in cold-acclimated fish, hepatocytes from 10- and 20 degrees c-acclimated animals did not differ in cellular weight, dry weight, or protein content. endogenous rates of oxygen consumption and respiratory control ratios were independent of acclimation temperature. there was no effect of temperature on triacy ...19846720921
hair cell orientation and a possible intraepithelial growth of the macula lagenae in the inner ear of the european eel.the hair cell orientation of the macula lagenae in eels at three different stages of life was examined with the light microscope. part of the posterior periphery of all three stages was occupied by a few rows of sensory cells having their kinocilium pointing in a direction opposite to the direction of the adjacent sensory cells. the width of this peripheral belt remained the same at all three stages of life, in spite of a considerable growth of the sensory epithelium, and the belt was always con ...19846145122
iron-rich particles in european eel (anguilla anguilla l.).magnetic material in the european eel (anguilla anguilla l.) was investigated by a combination of magnetic susceptibility measurements, energy dispersive x-ray fluorescence analysis and transmission electron microscopy. it was shown that the magnetic material is associated with iron. the main part of the iron is present in the form of iron-rich particles with irregular shapes about 100-3000 a large. the structures of magnetite (fe3o4), hematite (alpha-fe2o3) and alpha-iron (bcc structure) were i ...19846148194
effects of aconitine and veratrine on the isolated perfused heart of the common eel (anguilla anguilla l.).the effects of two alkaloids: aconitine and veratrine have been investigated in isolated perfused heart of the common eel (anguilla anguilla l.). low concentrations (less than 10(-6)m) of aconitine induced a decrease of the heart rate where high concentrations (greater than 10(-6)m) produced a tachycardia and finally led to a depolarization of cardiac cells. veratrine induced a decrease of the heart rate depending on the concentration. a cardiac arrest was observed with high concentrations (grea ...19846144445
storage and release of catecholamines by nervous endings in the isolated heart of the eel (anguilla anguilla l.).experiments performed on isolated perfused hearts of the eel (anguilla anguilla l.) showed that the heart spontaneously released catecholamines (i.e. adrenaline, noradrenaline, dopamine) suggesting that they take part in the cardiac regulation. stimulation of cardiac vagus branches significantly increased catecholamines levels, measured in a perfusion medium and simultaneously the heart rate and the systolic pressure. the effect of desmethylimipramine showed that the catecholamines were released ...19846141873
pineal neural connections with the brain in two teleosts, the crucian carp and the european eel.the neural connections between the pineal organ and the brain were investigated in two teleost species: the crucian carp and the european eel. horseradish peroxidase (hrp) was administered into the pineal parenchyma in vivo or in vitro. after 12-96 hours, the brains were fixed, and hrp was reacted in frozen sections with either diaminobenzidine (dab) or hanker-yate's reagent. the hrp had entered the pineal neurons, and had labeled their axonal processes (the pineal tract) in a golgi-like manner. ...19846085876
fish growth hormone enhances peripheral conversion of thyroxine to triiodothyronine in the eel (anguilla anguilla l.).in the eel, a low dose of tilapia growth hormone (tgh) (45 ng/g body wt), like ovine gh (ogh), induces a decrease in plasma thyroxine and a concomitant increase in plasma triiodothyronine, which result from a stimulation of peripheral conversion of thyroxine to triiodothyronine. salmon prolactin (sprl), unlike ovine prl (oprl), has no such action. recognition of this specific action of growth hormone (gh) on production of active thyroid hormone (t3) opens up a new approach to the problem of the ...19846510691
control of renal and adrenocortical function by the renin-angiotensin system in two euryhaline teleost fishes.plasma ions and cortisol levels were measured sequentially during the adaptation of european eels (anguilla anguilla) from fresh water (fw) to sea water (sw). the importance of the renin-angiotensin system in the regulation of this adaptation was assessed using captopril (sq14225, an inhibitor of angiotensin i-converting enzyme). the effects of captopril on renal function in fw- and sw-adapted trout were also examined. during the first 5 hr in sea water, plasma levels of cortisol in eels increas ...19853886478
the existence of three different viral agents in a tumour bearing european eel (anguilla anguilla). 19853922177
further observations on the presence of wandering phagocytes within the teleostean retina.a previous report by this author has noted the presence of wandering phagocytes at the photo-receptor-retinal epithelial interface in five teleostean species. a further 5 species have now been investigated by electron microscopy and again all specimens examined consistently show the presence of this population of phagocytes. the new species studied are the goldeye (hiodon alosoides), the yellow eel (anguilla anguilla), the archer fish (toxotes jaculatrix), the goldfish (carassius auratus) and th ...19854073522
retinal fine structure in the european eel anguilla anguilla. iv. photoreceptors of the yellow eel stage.the complex life cycle of the european eel (anguilla anguilla) involves a long catadromous migration during which the eye undergoes a number of morphological alterations. this report deals with the fine structure of the photoreceptors of the yellow eel stage and is part of a comparative study of the retina of the eel during the major stages of its life cycle. the photoreceptors of the yellow eel are easily divisible into rods and single cones and the rods at least appear to be capable of retinom ...19853993962
comparative aspects of circulating erythrocytes in the trophic and reproductive phases of european eel. ultrastructure and cytochemistry.different cytochemical and morphological parameters were used to compare the functional patterns of the erythrocytes in the transition from the trophic (yellow eel) to the reproductive (silver eel) phases of european eel (anguilla anguilla l.). data on the nucleus were obtained by microdensitometric (feulgen reaction) and cytofluoremetric (propidium iodide and hoechst 33342 fluorochromization) evaluations of dna staining intensity. in the silver eel, chromatin condensation was more heterogeneous ...19852935220
live and reactivated motility in the 9+0 flagellum of anguilla sperm.the sperm flagella of the eel, anguilla anguilla, are capable of vigorous motion in spite of having an axoneme with reduced structure that lacks the outer dynein arms, radial spokes and spoke heads, the two central tubules and the central tubule projections that are all part of the standard "9+2" axoneme. these sperm progress forward rapidly as a result of the propagation of helicoidal waves distally along the flagellum. their flagellar beat frequencies are high, 93 hz at 21 degrees c, and they ...19852931175
detection of endocrine cells by immunofluorescence method in the gastroenteropancreatic system of the adult eel, glass-eel, and leptocephalic larva (anguilla anguilla l.).five antisera against insulin (ins), glucagon (glu), somatostatin (srif), met-enkephalin (met-enk), and serotonin (5-ht) were used for immunofluorescence detection of endocrine cells in pancreas and gastrointestinal tract (git) of the european eel (anguilla anguilla l.) at three stages of development (leptocephalic larva, glass-eel, and adult eel). comparable distribution of endocrine cells was observed for adults and glass-eels. in their pancreatic islets, positive immunoreactions were obtained ...19852861142
seasonal variations in hematocrit, red cell hemoglobin and nucleoside triphosphate concentrations, in the european eel anguilla anguilla.eels acclimatized in nature show a significant annual variation in erythrocytic guanosine triphosphate (gtp) concentration, temperature range 0.5-17 degrees c. a similar but smaller annual variation is also present in eels acclimated in the laboratory at constant temperature, 17 degrees c. hematocrit and blood oxygen capacity showed no seasonal variation. natural minimal and maximal red cell gtp concentrations were found at the end of the dormancy period (march) and in the late summer, respectiv ...19852859960
on the heterogeneity of purkinje neurons in vertebrates. cytochemical and morphological studies of chromatin during eel (anguilla anguilla l.) life cycle.the relationship between the heterogeneity of purkinje cell chromatin and the functional involvement of cerebellum has been analyzed comparing two stages of eel life cycle (yellow eel and silver eel) which are characterized by a different degree of swimming activity. the dna content and the chromatin condensation have been studied by means of microdensitometry (feulgen-dna, feulgen-dna/area), microfluorometry (dna after intercalation with propidium iodide at low and high concentration) and elect ...19852410490
activation of trout gill amp deaminase by an endogenous proteinase--iii. comparative studies on the gill amp deaminase from different fresh water and sea water teleosts.the effects of monovalent cations and inorganic phosphate, on gill amp deaminase, were compared in different fresh water and sea water stenohaline and euryhaline teleosts. generally, sea water species displayed a lower sensitivity to these effectors than fresh water species. during salinity changes, the sensitivity of gill amp deaminase to cations and phosphate were modified proportionally to the tolerance of a given species to variations of environmental salinity. in particular, these parameter ...19863533411
the relationship of eel anguilla anguilla (l.) body size, lipid, protein, glucose, ash, moisture composition and enzyme activity (aldolase).body composition: protein, lipid, ash, moisture; and enzyme activity (aldolase) were studied in european eels (anguilla anguilla) of various sizes. the fish were brought to the laboratory as glass eels (0.35 g) and maintained under controlled conditions (23 degrees c) for one year. after one year of growth, various sizes (between 9 and 420 g) were found. significant correlation coefficients of the equation w = a ln c + b (where w = body weight, in g; c = composition, % or activity, u; and a,b ar ...19862875842
effects of hypophysectomy on the testis of the european eel (anguilla anguilla l.).the pituitary control of testis activity in the freshwater silver european eel (anguilla anguilla l.) was investigated by study of some variations of gonad structure and particularly changes in plasma levels of testosterone and 11-oxotestosterone (radioimmunoassay) following hypophysectomy. germ cells comprised only spermatogonia, which were associated with sertoli cells to form cysts. no mitotic activity of spermatogonia was observed. gonadosomatic index (gsi) was low. plasma levels of the main ...19863770433
the ca++ permeability of the apical membrane in neuromast hair cells.the mechanosensitivity of eel (anguilla anguilla) neuromasts was measured by the impulse responses of single afferent nerve fibers to mechanical stimuli. it is dependent on the potential across the skin and on the ions in the water outside the apical membrane of the sensory cells. the mechanosensitivity decreases to zero when the skin is polarized by 10-100 mv cathodal dc (skin surface negative); it increases with increasing (10-60 mv) anodal dc and remains remarkably constant with higher polari ...19863735160
cutaneous and gill o2 uptake in the european eel (anguilla anguilla l.) in relation to ambient po2, 10-400 torr.the partition of o2 uptake between gills and skin was examined in the freshwater eel (anguilla anguilla l.) at ambient po2 ranging from hyperoxia (po2 = 400 torr) to severe hypoxia (po2 = 10 torr), using a technique of open-flow respirometry. all the expired water was collected, and the ventilatory flow and the mixed expired water po2 were directly measured. the ventilatory water flow decreased moderately in hyperoxia, increased markedly between normoxia and 40 torr, and below 40 torr, hypervent ...19863797848
the effects of neurohypophysial hormones on the vascular resistance of the isolated perfused gill of the european eel, anguilla anguilla l.arginine vasotocin (avt) and oxytocin (oxy), in the dose range of 2 x 10(-13)-2 x 10(-8) mol, were found to be potent vasoconstrictors of the arterioarterial pathway of isolated perfused eel gills. avt was significantly (p less than 0.05) more potent than oxy, as indicated by the results of both dose- and concentration-response curves. isotocin (it) and arginine vasopressin (avp) were unable to elicit a vascular response at doses of up to 2 x 10(-8) mol. the arteriovenous component of branchial ...19863557080
na-dependent d-glucose and l-alanine transport in eel intestinal brush border membrane vesicles.brush border membrane vesicles (bbmv) were prepared from eel (anguilla anguilla) intestine by a mg-ethylene-glycol-bis(beta-aminoethylether)-n,n'-tetraacetic acid precipitation technique; the bbmv were enriched 16, 12, and 13 times in leucine aminopeptidase, maltase, and alkaline phosphatase activities with respect to the starting mucosal scraping. d-[3h]glucose and l-[3h]alanine transport by these vesicles was studied by a rapid filtration technique. d-glucose uptake was stimulated by a transme ...19863752280
the relationship of saccular efferent neurons to the superior olive in the eel, anguilla anguilla.in the eel, horseradish peroxidase was applied to the saccular ramus of the eight nerve to label auditory efferent neurons and was injected into the torus semicircularis to identify the superior olive. efferent somata cluster close to the lateral lemniscus. the superior olive is also associated with the lateral lemniscus and is situated just rostral to and contiguous with the efferent population. efferent cells can be distinguished from superior olivary neurons because of their larger size and t ...19863725216
the effect of 3,3',5-triiodo-l-thyronine and 17-α-methyltestosterone on growth and body composition of the glass stage of the eel (anguilla anguilla l).this study was undertaken to determine the influence of orally administered 3,3',5-triiodo-l-thyronine (t3) or 17-α-methyltestosterone (mt) on growth and body composition of the eel (anguilla anguilla l.) during the glass stage.elvers receiving 20 or 40 ppm of t3 in the food weighed significantly more (p < 0.05) than controls. however, after 61 days of treatment a dosage of 60 ppm was not efficacious.terminal percentages of body protein were significantly lower (p < 0.05) in elvers that received ...198624234666
mitochondrial dna differentiation in north atlantic eels: population genetic consequences of an unusual life history pattern.a survey of restriction site polymorphism in the mitochondrial dna (mtdna) of the american eel anguilla rostrata showed no genetic divergence among samples from a 4000-km stretch of north america coastline. lack of geographic differentiation in mtdna over such a large area contrasts sharply with results for terrestrial and freshwater vertebrates and is most likely attributable to the extraordinary life history of these catadromous fishes, which involves perhaps a single spawning population in th ...198616593712
ovarian metabolic pathways of steroid biosynthesis in the european eel (anguilla anguilla l.) at the silver stage.ovarian slices of the european eel at the silver stage were incubated with 4 tritiated precursors (pregnenolone, progesterone, androstenedione, testosterone) in the presence or not of an inhibitor of 11 beta-hydroxylase activity, metopirone. ether extracts were submitted to a gradient elution chromatography on celite columns. isolated peaks were identified by isopolarity on tlc, microchemical reactions and recrystallization to constant specific activity. interpretation of the results shows that ...19863517503
is mucus involved in biocrystallization? study of the intestinal mucus of the sea-water eel anguilla anguilla l.freeze-dried intestinal mucus of sea-water-adapted eels was analysed by scanning electron microscopy (sem) and x-ray microanalysis. calcite crystals were observed in the mucus fibres; their concentration increased along the hindgut. random sem observations made in situ indicated that mucus fibres were involved in the genesis of these crystals. calcium-rich mucus globules were found fused inside crystal matrices. single typical rhombohedric crystals of various complexity appeared within the mucus ...19863757019
[accumulation of cyclic adenosine monophosphate in the ovary of the eel (anguilla anguilla l.) in vitro under the effect of carp gonadotropin or ovine lutropin: kinetics and thermodependence].cyclic amp (camp) in pieces of eel ovary was greatly increased in vitro by the gonadotropin (cgth) of carp, another teleost fish; after one hour at 20 degrees c, maximal stimulation = 31.7 and e.d. 50 = 0.08 micrograms/ml. ovine lutropin (olh) had less effect (maximal stimulation: 2.35; e.d. 50: 1.42 micrograms/ml); its action suggested that it involved a subfraction (olh/cgth rac) of the receptor-adenylate cyclase (rac) systems which mediate the action of cgth. another difference was the percen ...19863012723
suppression of plasma thyroid hormone concentrations by cortisol in the european eel anguilla anguilla.female european eels, anguilla anguilla, were given a single intra-arterial injection via a catheter of cortisol hemisuccinate at doses ranging from 3.5 to 35 micrograms (15 to 150 micrograms/kg body wt), yielding mean plasma cortisol levels of 87-410 ng/ml 2 hr after injection. cortisol treatment (17.5 and 35 micrograms) significantly decreased plasma levels of thyroxine (t4) and triiodothyronine (t3) within 24 hr relative to those in control fish. cortisol treatment (35 micrograms) appeared to ...19862870843
[experimental approach to the role of the paratenic host in the circulation of the parasite bothriocephalus claviceps goeze, 1782 (cestoda, pseudophyllidea)].this article concerns an experimental work monitored in 5 species of fishes in the order to evaluate their value of paratenic hosts, in the cycle of bothriocephalus claviceps, a parasite of the eel, anguilla anguilla. the intestinal localisation and the lack of development of parasites are the two principal characters of this parasitism. the second character is sometimes contradicted. the effective evolution has been observed during 20 days. the more important losses of parasites coincide with t ...19863813425
the concept of specificity in the procercoid-copepod system: bothriocephalus claviceps (cestoda) a parasite of the eel (anguilla anguilla).this paper describes experimental work on parasite specificity in the copepod-procercoid system of bothriocephalus claviceps. two criteria were used to characterize five potential host species macrocyclops albidus, macrocyclops fuscus, eucyclops serrulatus, acanthocyclops robustus and macrocyclops viridis viridis. the first criterion involves susceptibility of the copepods to infection. the results show random or aggregative distributions and variable susceptibilities according to the species. w ...19873575289
cerebrospinal fluid-contacting neurons, ciliated perikarya and "peptidergic" synapses in the magnocellular preoptic nucleus of teleostean fishes.the magnocellular preoptic nucleus of fishes (anguilla anguilla, amiurus nebulosus, cyprinus carpio, carassius auratus, ctenopharyngodon idella, cichlasoma nigrofasciatum) has been studied by light and electron microscopy. two kinds of neurons were found: a) large, electron-dense, gomori-positive cells with moderate acetylcholinesterase (ache) positivity which contain granulated vesicles of 1400 to 2200 a (in average 1600 to 1800 a), adn b) small, strongly ache-positive, electron-lucent neurons ...1987174818
co-existence of congeneric species of acanthocephala: acanthocephalus lucii and a. anguillae in eels anguilla anguilla in ireland.a population of eels anguilla anguilla from lough derg, r. shannon, ireland, harbouring infections of both acanthocephalus lucii and a. anguillae was studied over three years. both parasite species had the same intermediate host and eels appeared to be the only definitive host for a. anguillae. throughout the whole period, a. lucii was the dominant parasite, was over-dispersed throughout the eel population and most frequently occurred as a single species infection. a. anguillae was far less comm ...19873696765
co-localization and secretion of parathyrin of stannius corpuscles (immunoreactive parathyroid hormone) and of secretory glycoproteins including secretory protein-i in the european eel (anguilla anguilla l.).until recently, teleosts were considered to be devoid of parathyroids. we showed recently that the corpuscles of stannius, that structurally have features in common with the parathyroid gland, produce a molecule resembling mammalian parathyroid hormone (pth). we refer to this molecule as parathyrin of corpuscles of stannius (pcs). parathyroid secretory protein-i (sp-i) is an acidic glycoprotein, probably identical to adrenal chromogranin a, that is co-stored and co-secreted with pth. in the pres ...19873504727
daniconema anguillae gen. et sp. n., a new nematode of a new family daniconematidae fam. n. parasitic in european eels.a new nematode genus and species, daniconema anguillae gen. et sp. n., is described from the serosa of the swimbladder and from the intestine of eels (anguilla anguilla (l.] from denmark (lake esrum, northern zealand); a new family daniconematidae fam. n. is established to accommodate it. the hitherto monotypic family daniconematidae shows affinities with the skrjabillanidae; in contrast to the latter, the new family is characterized by the absence of a buccal capsule, by the presence of anus in ...19873428765
the nutrition of the gill parasitic monogenean pseudodactylogyrus anguillae.a histological and histochemical study of ingested food material, energy stores and enzymes in the monogenean pseudodactylogyrus anguillae, parasitizing the gills of the european eel (anguilla anguilla) is presented. it was found that mucus, epithelial cells and blood from the gills were ingested. glycogen deposits were small and primarily located in the parenchyma and to a minor extent in the vitellariae. numerous globules of neutral lipids were found in the vitellariae. a marked esterase activ ...19873422977
detection of surface carbohydrates on pneumocystis carinii by fluorescein-conjugated lectins.lectins react with a wide range of different carbohydrates (table 1). even so-called monospecific anti-h(o) lectins from lotus tetragonolobus, ulex europaeus, and anguilla anguilla react not only with the anti-h determinant but also with several fucosylated carbohydrates. consequently, the type of lectin receptor existing on the surface of pneumocystis carinii should be determined, because only a carbohydrate analysis can demonstrate the kind of carbohydrates which exist on the cell surface of t ...19873125541
parasitological study of a population of tiber river eels (anguilla anguilla).a study was conducted on the parasitofauna of anguilla anguilla caught in the section of the tiber river south of rome (italy). the sample examined consisted of 417 specimens that were classified by stage (elver, young yellow eel, yellow eel and silver eel) and season of sampling. the following species were identified: trypanosoma granulosum, eimeria anguillae, myxidium giardi, sphaerospora reichenowi, myxobolus sp., trichodina anguilli, ichthyohodo sp., gyrodactylus anguillae, bothriocephalus c ...19873508508
induction of spermatogenesis and spermiation by a single injection of human chorionic gonadotropin in intact and hypophysectomized immature european eel (anguilla anguilla l.).intact and hypophysectomized male silver eels (anguilla anguilla) in fresh water received a single injection of human chorionic gonadotropin (hcg) (250 c) or solvent (0.15 m nacl). no effect of solvent was observed. spermatogonia proliferated in testis of hcg-treated intact or hypophysectomized eels. one month after the injection, primary and secondary spermatocytes were found. after 3 months, numerous spermatozoa were present. in hypophysectomized eels, hcg was also effective even though maturi ...19873666426
estradiol has inverse effects on pituitary glycoprotein hormone alpha-subunit messenger ribonucleic acid in the immature european eel and the gonadectomized rat.in teleosts, the pituitary contains a single glycoprotein gonadotropic hormone (gth) composed of two dissimilar alpha- and beta-subunits. the european eel, anguilla anguilla l, is sexually immature at the silver stage due to a deficiency in gth synthesis and secretion. in previous studies we (s.d., ya.f.) have demonstrated a strong stimulatory action of estradiol (e2) on eel pituitary gth content. in contrast, we (r.c., m.j.) have shown that in the rat e2 negatively regulates gonadotropin subuni ...19872441980
the effect of pressure on the lateral swimming muscle of the european eel anguilla anguilla and the deep sea eel histiobranchus bathybius; results of challenger cruise 6b/85.1. the viability of histiobranchus lateral muscle was prolonged up to 7 times by recompression of the tissue. 2. the maximum twitch contraction force of both anguilla and histiobranchus was recorded at a pressure between 150 and 350 atm. at 1 atm anguilla developed 60% maximum force and histiobranchus 10-20% maximum force. 3. twitch contraction time doubled for a pressure increase of 400 atm. this effect is predicted to halve the maximum swimming speed at 4000 m and is discussed in relation to m ...19872892634
effects of hydrostatic pressure on the motor activity of fish from shallow water and 900 m depths; some results of challenger cruise 6b/85.1. two species of benthic fish from 900 m depths (90 atm pressure), trachyscorpia cristulata echinata and synaphobranchus kaupi, are shown to be adapted to their normal, high ambient pressure. 2. their condition improves when they are restored to their normal pressure after experiencing decompression in a trawl and they undergo convulsions at 150 atm. 3. this contrasts with the response of shallow water species (salmo salar, pleuronectes platessa, anguilla anguilla and gadus morhua) which convul ...19872892630
effect of dietary carbohydrate source on soluble protein glucose concentration and enzyme activity (aldolase) of european eels (anguilla anguilla l.).this study was undertaken to determine the influence of dietary carbohydrate sources: wheat meal, bread meal, soluble corn starch, native potato starch and sorghum meal, on soluble protein, enzyme activity (aldolase) and glucose concentration in muscle and liver of european eels (anguilla anguilla). there was less soluble protein in both muscle and liver of eels fed 30% wheat meal or bread meal than the other experimental groups. however, eels fed 30% bread meal or soluble corn starch had a high ...19872886257
localization of beta-hydroxysteroid dehydrogenase in anguilla anguilla testis.the histochemical reaction for 3 beta-hydroxysteroid dehydrogenase was applied to glutaraldehyde fixed eel testis and successively processed for transmission electron microscopy. the reaction product was found only on the smooth endoplasmic reticulum and in the intermembrane space of mitochondria of the leydig cells of hcg treated silver eels. the positive cytochemical reaction appears to be coupled with an enlargement of the leydig cells and an increase of their smooth endoplasmic reticulum.19872443116
testis cytological structure, plasma sex steroids, and gonad cytosol free steroid receptors of heterologous gonadotropin (hcg)-stimulated silver eel, anguilla anguilla l.complete testicular maturation was induced in silver eels, kept at 24 degrees in fresh water, by a single injection of 1000 i.u. of heterologous gonadotropin (hcg). each week, for 4 weeks, some eels were examined for testis structural pattern, plasma sex steroids, and gonad cytosol steroid receptors. the first effect of the hcg was on the tubular organization of the testis, followed by spermatogenesis. plasma androgens were not detectable in the untreated eels, whereas a peak was detected a week ...19873817439
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