| cytology and neuroendocrine relations of the pituitary of the dogfish, scyliorhinus canicula. | | 1975 | 1780 |
| electron microscopic study of post-thyroidectomy changes in the ventral lobe of the adenohypophysis in very young spotted dogfish (scyllium canicula, chondrichthyes). | | 1978 | 571382 |
| [electron microscope observation of "thyroidectomy cells" in the hypophyseal ventral lobe of a chondrichthyan fish, the small spotted dogfish, scyllium canicula cuv]. | in the adenohypophysis of very young spotted dogfish, only one kind of granulated cells show strcutural changes following thyroidectomy: the small granule cells of the ventral lobe (granule diameter about 110 nm). these cells are similar to the thyrotrophs of other vertebrates, and well distinct from the supposed gonadotrophs found in the same lobe. | 1978 | 99253 |
| [metabolism of glucosamine in the liver of scyliorhinus canicula (selachian)]. | (1) the metabolism of the glucosamine was studied in the liver of s. canicula, after injection of d-(1-14c) glucosamine into the animal. (2) the labelled acid-soluble derivatives were separated by ion exchange columns and characterized by chromatography and electrophoresis, and were identified as glucosamine, glucosamine 6-p, n-acetylglucosamine, n-acetylmannosamine, n-acetylneuraminic acid, n-acetylglucosamine 6-p, n-acetylglucosamine 1-p, n-acetylmannosamine 6-p, udp-n-acetylglucosamine, udp-n ... | 1976 | 64135 |
| zinc in the gills of the dogfish (scyliorhinus canicula l.) related to experimental aquatic zinc pollution. | | 1979 | 40735 |
| occurrance of dopamine in the chromaffin tissue of a cartilaginous selachian fish: scyliorhinus canicula. | | 1978 | 25737 |
| studies on a primitive cerebellar cortex. i. the anatomy of the lateral-line lobes of the dogfish, scyliorhinus canicula. | | 1977 | 15265 |
| a study of the unidirectional fluxes of na and cl across the gills of the dogfish scyliorhinus canicula (chondrichthyes). | the gills of the dogfish scyliorhinus canicula are more permeable to cl than to na. in sea water, influx of na and cl exceeded the efflux of these ions. under these conditions the fish were slightly electronegative, by about 2 mv, to the external solution. the net accumulation of cl could be accounted for by diffusion along the observed electrochemical gradient byt the movement of na into the fish was more consistent with an electrically neutral active na transport mechanism (using the ussing fl ... | 1976 | 6612 |
| ventilatory response to hypercapnia in the larger spotted dogfish scyliorhinus stellaris. | dogfish were exposed to sudden changes of pco2 in inspired seawater. during hypercapnia breathing frequency remained constant, but gill ventilation was transiently increased to about 140% of control levels in the 1st h. o2 uptake was significantly increased also, but returned to the initial level before nomalization of gill ventilation. in contrast to the transient rise in gill ventilation and o2 uptake, arterial po2 was increased for the whole period of hypercapnia. hypercapnia results in a mar ... | 1976 | 4974 |
| the effect of splenectomy on the hematology and on the activity of delta-aminolevulinic acid dehydratase (ala-d) in hemopoietic tissues of the dogfish, scyliorhinus canicula (elasmobranchii). | | 1975 | 1175 |
| effects of hypophysectomy on vitellogenesis in the elasmobranch scyliorhinus canicula l. | | 1978 | 730043 |
| the effects of oestrogen treatment on certain plasma constituents associated with vitellogenesis in the elasmobranch scyliorhinus canicula l. | | 1978 | 720816 |
| ultrastructure of the dogfish adenohypophysis. | granular hormone-producing cells and agranular cells (stellate cells, including giant and pericavitary cells) were electron microscopically studied in the hypophysis of the small spotted dogfish (scyllium canicula) up to several months after hatching. comparisons of results obtained in embryos, newly-hatched fish and adults show an increase of the mean granule diameter in the four major endocrine cell types. small granule cells which are present in all lobes are especially numerous in the ventra ... | 1978 | 719710 |
| organization of the reticular formation in the dogfish scyliorhinus canicula [proceedings]. | | 1978 | 690935 |
| [ultrastructural and chemical study of the chromatin during spermiogenesis of the fish scyliorhinus caniculus (l.) (author's transl)]. | electron microscopic, cytochemical and biochemical techniques were applied to study structural aspects and changes in nuclear components during the spermiogenesis of scyliorhinus caniculus. five major stages of nuclear differentiation were recognized and characterized by variations in the organization and chemical properties of chromatin. stage i is analogous to a somatic nucleus with heterogeneous chromatin. at the second stage, the nuclear content is dispersed but the chromatin fibers are of t ... | 1978 | 648696 |
| steroid biosynthesis by the testes of the dogfish scyliorhinus caniculus. | | 1978 | 620920 |
| biochemical research on oogenesis. rna accumulation during oogenesis of the dogfish scyliorhinus caniculus. | | 1978 | 620878 |
| permeability coefficients of the egg-case membrane of scyliorhinus canicula l. | the cleidoic egg-case of the dogfish appears to have a highly porous and permeable outer membrane, the pore radius being computed to be 13.6 a. it does not present any physiological barrier to small molecules and therefore constitutes an open ionic and osmotic system for the embryo. being a porous protein membrane it may be of value as a model for molecular transport mechanisms. | 1978 | 569596 |
| isolation of brush border membranes in vesicular form from the intestinal spiral valve of the small dogfish (scyliorhinus canicula). | a simple, rapid method for the preparation of purified brush border membranes in vesicular form from rabbit kidney proximal tubules has been applied with closely similar results to the intestinal spiral valve of the small dogfish (scyliorhinus conicula). since the dogfish belongs to one of the most ancient species of fish, it may be suggested that the method is generally applicable to all species later evolved which possess a brush border membrane at the mucosal surface of the cells of the intes ... | 1979 | 454603 |
| steroid-protein interactions in nonmammalian vertebrates. i. elasmobranch steroids-binding protein (e. sbp) in dogfish serum (scyliorhinus canicula). | | 1975 | 235485 |
| effects of hypothalamic extracts, neurotransmitters and synthetic hypothalamic releasing hormones on adenylyl cyclase activity in the lobes of the pituitary of the dogfish (scyliorhinus canicula l.). | neutralized acid extracts of the median eminence of the dogfish hypothalamus were found to cause a dose-related activation of adenylyl cyclase in all lobes of the dogfish pituitary. equal concentrations of extracts of extrahypothalamic areas of the dogfish brain did not activate the enzyme. the putative neurotransmitters melatonin, serotonin, adrenaline, noradrenaline, dopamine and acetylcholine were without effect, as were the prostaglandins e1 and e2. the effects of synthetic mammalian hypotha ... | 1975 | 234999 |
| the effect of urea, thiourea and acetamide on the renal and branchial enzyme-pattern of the dogfish scyliorhinus canicula. | | 1976 | 131669 |
| studies on the purification and properties of gonadotrophin from ventral lobes of the pituitary gland of the dogfish (scyliorhinus canicula l.). | | 1978 | 738601 |
| [cutaneous respiration in a selachian (scyliorhinus caniculus l.)]. | cutaneous oxygen consumption (mo2) and cutaneous oxygen uptake from the external medium were investigated in an elasmobranch scyliorhinus caniculus l. in spite of an important mo2 (2.75 +/- 0.28 nmol.mn-1 cm-2 ; n=6) a positive net flux of oxygen through the skin takes place (2.98 +/- 0.33 nmol. mn-1 .cm-2). the skin of the dogfish in an exchanger for oxygen supplying 10% of oxygen requirements of other organs of the body in these experimental conditions (t = 13 degrees c). | 1978 | 97014 |
| gonadotrophic hormone in the pituitary gland of the dogfish (scyliorhinus canicula l): distribution and physiological significance. | | 1978 | 738602 |
| [embryonal development of the brain of the shark scyliorhinus canicula (l.). i. formation of the shape of the brain, the migration mode and phase and the structure of the diencephalon]. | brain structure of the shark scyliorhinus canicula has been studied on the basis of a series of embryonic stages. the incubation time was 157 days in average (under constant conditions of 15 centigrades and density of 1.026). 1. the first predominant characters of the external brain shape are the optic tectum, cerebellum, telencephali hemispheres and oculomotor root. in addition, the brain axis is characterized by new flexures in the cerebellar and prosencephalic level. a nuchal flexure in absen ... | 1978 | 739140 |
| golgi cells of the cerebellum of the dogfish, scyliorhinus canicula (elasmobranchs): a golgi and ultrastructural study. | golgi cells of the dogfish cerebellum were studied using both golgi methods and electron microscopy. the arborization of their dendrites and axonal processes is limited to the granular layer, which in this species forms characteristic granular eminences. the dendrites are rather simple. however, the various axons of a golgi cell form a dense plexus of thin beaded processes whose complexity approaches that observed in the mammalian cerebellum. electron microscopy shows that the golgi cells are me ... | 1992 | 1281857 |
| [embryonal development of the brain of the shark scyliorhinus canicula (l.). ii. the optic tectum and its stratification]. | the stratification of the optic tectum of the shark scyliorhinus canicula is comparable to patterns of other vertebrates. thus it is possible to homologize part of the cortex layers with those described by p. ramon (1896) and huber & crosby (1933b). 1. as for other vertebrates, it makes sense to collect the large number of zones (layers) into three groups: periventricular, central and superficial. 2. ramon's periventricular zones 1--3 are distinct; fibrous zone 4 and cellular zone 5 are partiall ... | 1978 | 739141 |
| [embryonic development of the brain of scyliorhinus canicula (l.). iii. the optical system and adjacent nuclei in the tegmentum mesencephali]. | the ontogenesis of the optic system in the brain has been studied with reference to the general biology of the embryo and to the cytoarchitecture of the optic tectum. 1. sharks vary in terms of retinal structure (franz 1931). scyliorhinus shows densely packed and large cellular layers alternating with thin fiber layers. 2. the optic tracts, which are not excessively large, cross in the optic chiasm by approximately 95%. the optic fibers, forming a medial and a lateral tract, enter the tectum in ... | 1978 | 748452 |
| extracellular and intracellular ph with changes of temperature in the dogfish scyliorhinus stellaris. | larger spotted dogfish, scyliorhinus stellaris, were exposed to varied ambient temperature (t) in order to determine the behavior of extracellular ph (phe), pco2 and bicarbonate concentration as well as intracellular ph (phi) in three muscle types. phe was found to vary with temperature slightly less than expected on the basis of the rule of constant relative alkalinity in juvenile (deltaph/deltat= -0.0148 per degree centigrade) as well as in adult (deltaph/deltat= -0.0136) fish. the absolute ph ... | 1976 | 7011 |
| bicarbonate exchange between body compartments after changes of temperature in the larger spotted dogfish (soyliorhinus stellaris). | intracellular/extracellular and extracellular/sea-water bicarbonate exchanges were measured in larger spotted dogfish (sycliorhinus stellaris) exposed to 10 degrees c temperature step changes in a closed sea-water recirculation system. changes of the bicarbonate concentration in blood plasma (= extracellular space) and in the recirculating sea-water were monitored for 36 h after the temperature change. intracellular/extracellular transfer of bicarbonate was computed from bicarbonate changes in t ... | 1978 | 674895 |
| vestibular nuclei of the dogfish scyliorhinus canicula [proceedings]. | | 1977 | 894558 |
| the effect of sectioning cranial nerves v, vii, ixand x on the cardiac response of the dogfish scyliorhinus canicula to environmental hypoxia. | | 1977 | 908911 |
| hormonal control of steroidogenesis in an elasmobranch fish (scyliorhinus canicula l.): studies using a specific anti-gonadotrophic antibody [proceedings]. | | 1978 | 731155 |
| proceedings: responses of cerebellar nuclear neurones in the elasmobranch fish scyliorhinus canicula. | | 1976 | 948074 |
| hypercapnia and resultant bicarbonate transfer processes in an elasmobranch fish (scyliorhinus stellaris). | in order to test the effects of hypercapnia on the acid-base status of fish, larger spotted dogfish were exposed to sudden changes of pco2 in a closed seawater recirculation system. ph, pco2 and po2 were determined in arterial blood and seawater. the exchange of bicarbonate between extracellular space (ecs), intracellular space (ics), and seawater (sw) was obtained from changes of the total bicarbonate amount in ecs and sw. after fourfold increase of pco2 arterial ph fell markedly, but started t ... | 1976 | 13888 |
| respiration and circulation during swimming activity in the dogfish scyliorhinus stellaris. | a number of respiratory and circulatory parameters was measured in the larger spotted dogfish scyliorhinus stellaris before, during and after periods of spontaneous swimming. during swimming the gill ventilation was increased, mainly due to increased ventilatory stroke volume, the respiratory frequency showing a small rise only, and the cardiac output was increased at only slightly elevated cardiac frequency. coordination between cardiac, ventilatory or locomotor (tail-beat) rhythms was not obse ... | 1977 | 877447 |
| [stages of development and growth of the thyroid gland and adenohypophysis of the dogfish embryo (scillium canicula cuv.), a chondrichthyan fish]. | the thyroid morphology, histology, biometry and its anatomical connections are studied during the whole embryonic life in the small spotted dogfish (scyllium canicula cuv.). the first differentiation of the gland appears as a thickening of the pharyngeal floor, containing pas inclusions, at stage 10 mm. the first follicles are apparent at stage 30 mm. the thyroid volumetric relative growth is studied during the whole development and is compared with the absolute embryonic length growth. volumetr ... | 1976 | 1008560 |
| the impact of brain stem and cerebellum on a spinal reflex in the dogfish scyliorhinus canicula [proceedings]. | | 1976 | 1011151 |
| [morphological and histochemical aspects of the argentaffin and argentophilic cells in the gastric mucosa of scyliorhinus stellaris and scyliorhinus canicula]. | using histological and histochemical methods for the identification of biogenic amins, phenolic and indolic groups, and of substances with a proteine and carbohydrate nature, it has been possible to identify at least five types of endocrine cells in the gastric mucose of scyliorhinus stellaris and scyliorhinus canicula. one of these, a type i cell, localised mainly in the piloric portion, shows morphological and histochemical characteristics which are perfectly comparable with those of the enter ... | 1976 | 1023335 |
| studies on peptides. lxxi. synthesis of the octadecapeptide corresponding to the entire amino acid sequence of beta-melanocyte-stimulating hormone from the dogfish (scyliorhinus canicula). | | 1977 | 922986 |
| myelinated synapse-bearing cell bodies in the central nervous system of scyliorhinus canicula (l.) | some neurons of the anterior lateral-line lobe of dogfish (scyliorhinus) have synapse-bearing perikarya enclosed by layers of compact myelin. the identity of these cells, which have myelinated axons and unmyelinated, synapse-bearing dendrites, is unknown. | 1976 | 975222 |
| the effect of progressive hypoxia on respiration in the dogfish (scyliorhinus canicula) at different seasonal temperatures. | 1. dogfish were acclimated to 7, 12 or 17 degrees c and exposed to progressive hypoxia at the temperature to which they had been acclimated. during normoxia, the q10 values for oxygen uptake, heart rate, cardiac output and respiratory frequency over the full 10 degrees c range were: 2.1, 2.1, 2.1 and 2.5 respectively. increased acclimation temperature had no effect on cardiac stroke volume or systemic vascular resistance, although there was a decrease in branchial vascular resistance, pha and ph ... | 1975 | 1159356 |
| differential thermosensitivity and electric prepolarization of the ampullae of lorenzini. | in a single-fibre preparations the afferent discharges from prepolarized ampullae of lorenzini responding to graded temperature steps were investigated in the dogfish (scyliorhinus canicula). the transformation characteristics of the ampullary receptors, especially their differential thermosensitivity interfering with electrosensitivity, were analyzed. prepolarization significantly influenced the dynamic component of differential thermosensitivity, while the static component remained practically ... | 1976 | 986605 |
| effects of drugs and nerve stimulation on the spleen and arteries of two species of dogfish, scyliorhinus canicula and squalus acanthias. | the effects of drugs and nerve stimulation on the spleen of 2 species of dogfish have been examined by experiments with perfused spleens and isolated spleen and artery strips. adrenaline, noradrenaline and phenylephrine, acting via alpha adrenoceptors, constrict the perfused spleen of both species, thereby releasing erythrocytes, and contract the isolated spleen and artery strips. phenotolamine competitively antagonizes the excitatory effects of adrenergic agonists. the responses of the spleen t ... | 1975 | 1189932 |
| responses of neurones in the cerebellar corpus of the dogfish (scyliorhinus canicula). | | 1975 | 1123767 |
| topological analysis of the brain stem of the sharks squalus acanthias and scyliorhinus canicula. | | 1976 | 1270611 |
| renin and angiotensin converting enzyme in elasmobranchs. | renin-like activity (rla) and angiotensin i converting enzyme-like activity (acela), the two key enzymes of the renin-angiotensin system (ras), were sought in the elasmobranch scyliorhinus canicula. renal extracts were desalted in a g-25 and eluted in a g-100 sephadex column (calibration 15,000-70,000). the fractions were concentrated in a vacuum device. a 48,000-mw fraction incubated with synthetic and porcine angiotensiongen generated angiotensin i estimated by ria. this same fraction was vaso ... | 1992 | 1327949 |
| [ultrastructure of interrenal (adrenocortical) cells of an elamobranch, the common dogfish (scyliorhinus caniculus l)]. | the interrenal (adrenocortical) cells of the common dogfish show the ultrastructural features characteristic of steroid hormone producing cells. their endoplasmic reticulum consists predominantly of smooth surfaced tubules. they are rich in mitochondria with tubular and vesicular cristae and in liposomes. this last characteristic differentiates them from the interrenal cells of teleosts, which are devoid of liposomes. in addition, the interrenal cells of the common dogfish are strikingly rich in ... | 1976 | 816552 |
| the roles of temperature and photoperiod in the response of the testis of the dogfish, scyliorhinus canicula l. to partial hypophysectomy (ventral lobectomy). | | 1977 | 863219 |
| endocrine control of the testis in the dogfish scyliorhinus canicula l. i. effects of partial hypophysectomy on gravimetric, hormonal and biochemical aspects of testis function. | the effect of removal of the individual pituitary lobes of the dogfish (scyliorhinus canicula l.), separately or together, on gravimetric, hormonal, and biochemical aspects of testis function was investigated. various groups of operations were performed at different times of the year and the fish kept for various lengths of time before autopsy. removal of the ventral portion resulted in a breakdown in an area of the testis which reflected degeneration of late spermatogonia. however, this effe ... | 1977 | 863221 |
| endocrine control of the testis in the dogfish scyliorhinus canicula l. ii. histological and ultrastructural changes in the testis after partial hypophysectomy (ventral lobectomy). | | 1977 | 863222 |
| different molecular forms of c-type natriuretic peptide isolated from the brain and heart of an elasmobranch, triakis scyllia. | the presence of a c-type natriuretic peptide (cnp) has been reported in the brain of mammals, birds, amphibians and teleost fishes, mostly as a 22-residue peptide (cnp-22). in the present study, we attempted to isolate natriuretic peptides from an elasmobranch, triakis scyllia, using a chick rectum-relaxant assay, and different molecular forms of cnp were found in the brain and heart. only cnp-22 was recovered from the brain, as is the case in other vertebrates. a large amount of prohormone (pro ... | 1992 | 1474339 |
| the primary structure of peptide y (py) of the spiny dogfish, squalus acanthias: immunocytochemical localisation and isolation from the pancreas. | 1. endocrine cells within islets, exocrine parenchyma and ductal epithelium in the pancreas of the spiny dogfish, squalus acanthias, were immunostained with an antiserum to the c-terminal region of mammalian neuropeptide y (npy). 2. radioimmunoassay of pancreatic extracts with the same antiserum detected immunoreactivity in the dorsal lobe (338 pmol/g) and ventral lobe (433 pmol/g). reverse phase hplc analysis of both extracts resolved a single immunoreactive peptide. 3. the primary structure of ... | 1992 | 1526112 |
| proceedings: connexions between the cerebellum and the reticular formation in the dogfish scyliorhinus canicula. | | 1975 | 1151885 |
| brainstem neurons projecting to different levels of the spinal cord of the dogfish scyliorhinus canicula. | neurons in the brain that project to different levels of the spinal cord in the dogfish scyliorhinus canicula have been identified by retrograde labelling with horseradish peroxidase. injections have been made at four different levels, namely, cervical (segments 3-6), pectoral (segments 16-18), pelvic (segments 34-36) and caudal (segments 60-80). labelled neurons were located in the diencephalon, mesencephalon and rhombencephalon. twenty nuclei contained labelled cells following cervical injecti ... | 1992 | 1555112 |
| purification and characterization of urotensin ii and parvalbumin from an elasmobranch fish, scyliorhinus canicula (common dogfish). | the caudal portion of the spinal cord of elasmobranch fish incorporates a diffuse neuroendocrine system. using an antiserum raised against urotensin ii from a teleost fish (goby) to facilitate purification, a peptide structurally related to urotensin ii was isolated in pure form from an extract of neuroendocrine tissue from the spinal cord of the european common dogfish, scyliorhinus canicula. the primary structure of the peptide was established as: asn-asn-phe-ser-asp-cys-phe-trp-lys-tyr-cys-va ... | 1992 | 1620290 |
| response of the ampullae of lorenzini to static combined electric and thermal stimuli in scyliorhinus canicula. | the effect of long-lasting electric currents on the lorenzinian ampullae at constant temperatures between and 25 degrees c was investigated in the dogfish (scyliorhinus canicula). steady state neural impulse patterns in single afferent units were analyzed by plotting interval length histograms and computing mean values and standard deviations for currents between -100 and +100 na. the mean values depended on temperature and on current strength; the relative standard deviations remained almost c ... | 1975 | 1170086 |
| distribution of fmrfamide-like immunoreactivity in the brain of the elasmobranch fish scyliorhinus canicula. | the distribution of fmrfamide-like-immunoreactive peptides was investigated in the brain and pituitary of the elasmobranch fish scyliorhinus canicula using the indirect immunofluorescence technique. fmrfamide-immunoreactive cells and fibers were mainly observed in the telencephalon and the diencephalon, while other brain structures were almost unstained. in the telencephalon, fmrfamide-like-containing neurons were seen in the caudal part of the area periventricularis pallialis, in the posterior ... | 1991 | 1687710 |
| immunohistochemical mapping of galanin-like immunoreactivity in the brain of the dogfish scyliorhinus canicula. | the distribution of galanin-like immunoreactivity in the brain of the dogfish scyliorhinus canicula was investigated using the indirect immunofluorescence technique. in the telencephalon, positive cells and fibers were located in the mid-caudal part of the area superficialis basalis, the n. septi caudoventralis and in the n. interstitialis commissurae anterioris. most of the galanin-containing neurons observed in the hypothalamus were located in the magnocellular preoptic nucleus. positive perik ... | 1991 | 1712470 |
| the optic tectum of the dogfish scyliorhinus canicula l.: a golgi study. | the optic tectum of the dogfish scyliorhinus canicula l. was studied by using the methods of nissl, reduced silver nitrate, golgi-aldehyde, and golgi-cox. six layers and eight types of neurons were recognized. these cell types are not restricted to one layer; in fact some are found in all six tectal layers. the types of cells found are a) monopolar, b) triangular, c) radial bipolar, d) horizontal fusiform, e) large tectal, f) small tectal, g) pyriform, and h) stellate cells. in at least six of t ... | 1991 | 1713234 |
| specialized presynaptic dendrites in the stratum cellulare externum of the optic tectum of an elasmobranch, scyliorhinus canicula l. | electron microscopy of the stratum cellulare externum of the optic tectum of an elasmobranch revealed the presence of two types of presynaptic dendrites in the neuropil as well as axo-dendritic synapses. in the dendro-dendritic or dendro-axonic synapses, the presynaptic process was a beaded dendrite. these findings support the view that the synaptic organization of the tectum in elasmobranchs is basically similar to that of higher vertebrates, rather than the classical opinion that it is less hi ... | 1991 | 1745411 |
| mercury in muscle tissue of lesser-spotted dogfish (scyliorhinus caniculus l.) from the north-east irish sea. | this paper reports concentrations of mercury in muscle tissue of lesser-spotted dogfish (scyliorhinus caniculus l.) from various locations within liverpool bay and the north-east irish sea. concentrations of mercury in fish muscle showed distinct spatial variation, with values from the northern sectors of the irish sea significantly lower than those for the southern area, particularly sites in liverpool bay and around the mouth of the mersey estuary. the data support the hypothesis that there ar ... | 1991 | 1754877 |
| fatty acid composition and lipoxygenase metabolism in blood cells of the lesser spotted dogfish, scyliorhinus canicula. | 1. the fatty acid composition of erythrocytes and leucocytes of the elasmobranch, scyliorhinus canicula, was determined so as to indicate substrate availability for eicosanoid formation. 2. leucocytes showed a greater degree of fatty acid unsaturation than the erythrocytes, with particularly high levels of docosahexaenoic acid (22:6,n-3). 3. the major eicosanoid precursors, arachidonic acid (20:4,n-6) and eicosapentaenoic acid (20:5,n-3), represented 13.9% and 5.2% of the total fatty acid, respe ... | 1991 | 1769212 |
| a c type natriuretic peptide is a vasodilator in vivo and in vitro in the common dogfish. | the effects of an elasmbranch cardiac c-type natriuretic peptide (dogfish cnp-22) on arterial blood pressure were investigated in vivo in chronically cannulated dogfish scyliorhinus canicula and in vitro by a myographic technique using the distal part of the first branchial artery. in-vivo dogfish cnp-22 caused a dose-dependent reduction in mean arterial blood pressure which was much more potent than that of alpha-human anp. in-vitro dogfish cnp-22 also caused a dose-dependent relaxation which w ... | 1992 | 1535362 |
| binding sites for tachykinin peptides in the brain and stomach of the dogfish, scyliorhinus canicula. | in membranes of dogfish brain and stomach, two binding sites for tachykinins were identified. one site specifically bound [125i]-bolton-hunter substance p (bh-sp) and the rank potency of tachykinins to compete for bh-sp binding revealed similarities with the rank potency of an nk1 receptor. the pharmacology of the other site, which specifically bound [125i]-bolton-hunter scyliorhinin ii (bh-scy ii), did not resemble any of the mammalian tachykinin receptors. the rank potency to inhibit bh-scy ii ... | 1991 | 1666186 |
| studies on rod horizontal cell s-potential in dependence of the dark/light adapted state: a comparative study in cyprinus carpio and scyliorhinus canicula retinas. | changes in light sensitivity, response time-course and electrical coupling of rod driven horizontal cells (rhc) were examined in the dark and light adapted states by intracellular recording. comparative analyses were made of two fishes from different photic environments. rhc of cyprinus carpio and external horizontal cells (ehc) of scyliorhinus canicula retinas showed similar changes of their electrical responses to light stimuli when the dark-adapted retina was light-adapted: a decrease in sens ... | 1991 | 1843752 |
| efficiency of energy conversion during shortening of muscle fibres from the dogfish scyliorhinus canicula. | force and heat production were measured during isovelocity shortening of tetanized white myotomal muscle fibres from the dogfish at 12 degrees c. for each fibre preparation a range of velocities was used. mechanical power was calculated from force x velocity of shortening. the rate of total energy output during shortening was evaluated as the sum of mechanical power and the rate of heat production. the ratio of mechanical power to total energy rate was taken as a measure of efficiency of energy ... | 1991 | 1919411 |
| cadmium induction of metallothioneins in several dogfish organs. | dogfish scyliorhinus canicula were exposed to 50 mg/l cd for 4 days for inducing metallothionein synthesis. spleen, pancreas, kidney and gonads were dissected out and metallothionein presence was checked by means of gel filtration chromatography in sephadex g-75 and sodium dodecyl sulphate polyacrylamide electrophoresis. in pancreas and kidney, a cadmium-binding protein with spectroscopical and electrophoretic properties similar to those of dogfish liver metallothionein was found. in the other o ... | 1991 | 1924966 |
| evidence of collagen in the egg capsule of the dogfish, scyliorhinus canicula. | | 1976 | 1261244 |
| isolation of high-molecular-weight c-type natriuretic peptide from the heart of a cartilaginous fish (european dogfish, scyliorhinus canicula). | a high-molecular-weight form of c-type natriuretic peptide (cnp) was isolated from both cardiac atria and ventricles of european dogfish, scyliorhinus canicula, and its primary structure was determined. the peptide consists of 115 amino acid residues, in which the c-terminal 22 residues show high homology to cnps identified to date. this is the first direct evidence for the presence of natriuretic peptide in the cartilaginous fish, and for the presence of cnp in an organ other than the brain. | 1991 | 1828036 |
| immunohistochemical localization of delta sleep-inducing peptide (dsip) in the brain and pituitary of the cartilaginous fish scyliorhinus canicula. | the distribution of delta sleep-inducing peptide (dsip) in the brain and pituitary of the cartilaginous fish scyliorhinus canicula was investigated using the indirect immunofluorescence technique. delta sleep-inducing peptide-like immunoreactive cell bodies were mainly observed in the nucleus lateralis tuberis of the hypothalamus. immunolabeled perikarya were also distributed in the nucleus lobi lateralis hypothalami and in the dorso-lateral wall of the recessus posterioris. most of these cells, ... | 1992 | 1437707 |
| coronary myointimal lesions in the dogfish shark scyliorhinus canicula. | proliferative lesions have been found in the coronary arteries of five specimens of dogfish shark (scyliorhinus canicula). three specimens lacked the internal elastic membrane and had a diffuse thickening of the intima obliterating most of the vascular lumen in several intramyocardial branches. two specimens had intimal nodules in one of the main coronary conal trunks, where breaking and splitting of the internal elastic membrane and fibrosis of the tunica media were observed. these lesions appe ... | 1991 | 1770177 |
| neuropeptide y-like immunoreactivity in the dogfish gastroenteropancreatic tract: light and electron microscopical study. | the 36 amino acid neuropeptide y (npy) has been examined in mammals and is mainly located in the nerves. its distribution in nonmammalian vertebrate and in some invertebrate nervous systems has been confirmed. using antisera raised to porcine npy, npy immunoreactivity has been localized in endocrine cells of the pancreas and gastrointestinal tract of two dogfish, scyliorhinus stellaris and scyliorhinus canicula. immunostained serial sections and cross-absorption experiments with related peptides ... | 1992 | 1398005 |
| the adult dogfish (scyliorhinus canicula l.) testis: a model to study stage-dependent changes in steroid levels during spermatogenesis. | the unit structure of the testis of scyliorhinus canicula l. is the seminiferous lobule arranged in topographically distinct zones and comprised of cysts formed by steroid-producing sertoli cells associated with germ cells at an identical stage of spermatogenesis. in this experiment, testicular tissues from different dogfish corresponding to the zones of lobules with spermatogonia (a), spermatocytes (b), early spermatids (c) and late spermatids (d) were dissected out and pooled. they were either ... | 1990 | 2177763 |
| glomerular bypass shunts and distribution of glomeruli in the kidney of the lesser spotted dogfish, scyliorhinus caniculus. | scanning electron microscopy of corroded resin casts of the renal vasculature of scyliorhinus caniculus has revealed a novel vascular pathway arising from the afferent arteriole and bypassing the glomerulus. this glomerulus bypass shunt occurred in 36% of the glomerular casts examined. the shunt ran to join a peritubular network of capillaries and thereby offers the potential to vary the degree of glomerular perfusion and control the proportion of active glomeruli. in 29% of glomeruli two effere ... | 1992 | 1423497 |
| secretory patterns of 1 alpha-hydroxycorticosterone in the isolated perifused interrenal gland of the dogfish, scyliorhinus canicula. | an isolated in-vitro perifused interrenal gland preparation from the dogfish scyliorhinus canicula was used to study production of quantitatively the major corticosteroid 1 alpha-hydroxycorticosterone (1 alpha-oh-b), measured by radioimmunoassay. basal secretory rates were 877.1 +/- 145 (s.e.m.) fmol/mg per 15 min (n = 14) and the preparation remained viable for up to 22 h, as reflected in a brisk response to 10 microm cyclic amp (camp) after this time. steroid production responded in a dose-dep ... | 1990 | 2168710 |
| structural characterization of neuropeptide y from the brain of the dogfish, scyliorhinus canicula. | a peptide of the pancreatic polypeptide (pp) family was isolated in pure form from the brain of an elasmobranch fish, scyliorhinus canicula (european common dogfish). the primary structure of the peptide was established as: tyr-pro-ser-lys-pro-asp-asn-pro-gly-glu10-gly-ala-pro-ala-glu-asp- leu-ala-lys- tyr20-tyr-ser-ala-leu-arg-his-tyr-ile-asn-leu30-ile-thr-arg- gln-arg-tyr-nh2. this sequence contains only two amino acid substitutions compared with pig neuropeptide y (npy) (gly for asp11 and lys ... | 1992 | 1523163 |
| immunohistochemical localization of calbindin-d28k in the brain of a cartilaginous fish, the dogfish (scyliorhinus canicula l.). | the occurrence and distribution of the vitamin-d-induced calcium-binding protein, calbindin-d28k, has been studied in the brain of a cartilaginous fish using immunohistochemical techniques. a strong immunoreactivity was found in the perikarya, dendrites and axons of neurons located in the nucleus interstitialis commissurae anterioris, the nucleus medialis of the left habenula, the thalamus dorsalis, the thalamus ventralis, the nucleus lobi lateralis, the nucleus interpeduncularis, the lobus vagi ... | 1990 | 2368582 |
| electrophoretic study of the caseinolytic activity of a pepsin from the dogfish scyliorhinus canicula. | electrophoretic patterns of casein and casein subfractions were studied following proteolysis by dogfish pepsin ii or calf chymosin. both enzymes hydrolyze the kappa casein subfraction with the production of kappa paracasein peptide. alpha s1 and beta subfractions hydrolysis is stronger with dogfish enzyme than with chymosin. it is concluded that, despite a broader specificity, the activity spectrum of dogfish enzyme is, in many respects, similar to that of calf chymosin. | 1989 | 2502192 |
| distribution of somatostatin and glucagon immunoreactive cells in the gastric mucosa of some cartilaginous fishes. | the comparative distribution of somatostatin- and glucagon-like-containing cells in the histomorphologically different gastric mucosae of the cartilaginous fishes heptranchias perlo, raja asterias, scyliorhinus canicula, squatina aculeata, and torpedo marmorata was immunocytochemically studied to demonstrate a possible interrelationship between these endocrine cells and/or other endocrine or nonendocrine cells. in the gastric mucosa, these open-type glucagon and somatostatin immunoreactive cells ... | 1989 | 2570006 |
| the renin-angiotensin system and vascular and dipsogenic regulation in elasmobranchs. | the role of a renin-angiotensin-like system (ras) in the regulation of blood pressure and drinking has been investigated in the elasmobranch, scyliorhinus canicula. injection of exogenous angiotensin ii produced, as expected, a vasopressor response, though injection of the converting enzyme inhibitor, captopril, alone produced little change in resting blood pressure. papaverine, a smooth muscle relaxant, reduced blood pressure which completely recovered within 30 min. a subsequent injection of c ... | 1989 | 2653953 |
| energetics and mechanics of contracting white myotomal fibres from dogfish, scyliorhinus canicula. | | 1989 | 2798483 |
| neuronal localization of immunoreactive adrenocorticotropin-like substance in the hypothalamus of elasmobranch fishes. | the occurrence and localization of adrenocorticotropin (acth)-like material in the brain of two species of elasmobranch fishes, scyliorhinus canicula and squalus acanthias, were studied by immunohistochemical techniques using an antiserum generated against human acth1-24. in both species immunopositive neurons and fibers were recognized in the basal hypothalamus mainly distributed in the nucleus lateralis tuberis, in which many of these elements were of the liquor-contacting type. a few acth-lik ... | 1987 | 2821456 |
| isolation of the tachykinin, des[ser1pro2]scyliorhinin ii from the intestine of the ray, torpedo marmorata. | a peptide with neurokinin a-like immunoreactivity was isolated from an extract of the intestine of an elasmobranch fish, torpedo marmorata. the primary structure of the peptide was established as ser-asn-ser-lys-cys-pro-asp-gly-pro-asp-cys-phe-val-gly-leu-met.nh2. this amino acid sequence is identical to that of residues (3-18) of scyliorhinin ii previously isolated from the intestine of the common dogfish (scyliorhinus canicula). the presence of the truncated peptide, lacking ser-pro, in the to ... | 1988 | 2847952 |
| alpha-melanocyte-stimulating hormone (alpha-msh) in the brain of the cartilagenous fish. immunohistochemical localization and biochemical characterization. | the distribution of immunoreactive alpha-melanocyte-stimulating hormone (alpha-msh) in the central nervous system and pituitary of the elasmobranch fish scyliorhinus canicula was determined by the indirect immunofluorescence and the peroxidase-antiperoxidase methods using a highly specific antiserum. perikarya containing alpha-msh-like immunoreactivity were localized in the dorsal portion of the posterior hypothalamus, mainly in the tuberculus posterioris and sacci vasculosus nuclei. immunoreact ... | 1988 | 2852362 |
| cd-, zn-, cu-binding protein in the elasmobranch scyliorhinus canicula. | a cd-, zn-, cu-binding protein was isolated from the liver of dogfish subjected to environmental experimental contamination (50 ppm cd). it was also found in liver from untreated fish. this protein has a high absorption at 250 nm and a low absorption at 280 nm, suggesting a mercaptide bond and a lack of aromatic amino acids. the sds-page pattern and changes in absorption spectrum on adding cd or lowering ph are found as for mouse mt. the protein contains cu and zn in control and cu, zn and cd in ... | 1985 | 2861043 |
| dogfish metallothionein--ii. electrophoretic studies and comparison with rat metallothionein. | a low-molecular weight metal-binding protein has been isolated and characterized as metallothionein in the liver of the dogfish (scyliorhinus canicula). this protein is present in both male and female animals and both control and cadmium-treated (both water and i.p. administration) animals as revealed by sds-page studies. dogfish metallothionein shows the same metal-dependent anomalous behaviour as rat metallothionein in sds-page. sds-page is a good method to identify a protein as metallothionei ... | 1986 | 2869881 |
| identification of pancreatic glucagon cells in the cartilaginous fish scyliorhinus canicula by ultrastructural immunocytochemistry. | the ultrastructural localization of glucagon in the presence of scyliorhinus canicula was investigated. we used a post-embedding immunoelectron microscopy method on pancreatic samples fixed in glutaraldehyde and osmicated before embedding. contrasting with uranyl acetate and lead citrate was also performed after immunolabelling, but best results were obtained with uranyl acetate only. glucagon-like immunoreactivity was located in round granules (300-600 nm) surrounded by a limiting membrane. the ... | 1990 | 1980056 |
| structural characterization and biological activity of a neuropeptide y-related peptide from the dogfish, scyliorhinus canicula. | a peptide of the pancreatic polypeptide (pp) family was isolated in pure form from the pancreas of an elasmobranch fish, scyliorhinus canicula (european common dogfish). the primary structure of the peptide was established as: tyr-pro-pro-lys-pro-glu-asn-pro-gly-glu10-asp-ala-pro- pro-glu-glu-leu-ala-lys-tyr20-tyr-ser-ala-leu-arg-his- tyr-ile-asn-leu30-ile-thr-arg-gln-arg-tyr.nh2. this sequence contains 86% amino acid sequence homology with human neuropeptide y, and the cooh-terminal region (res ... | 1991 | 2019251 |
| developing nephrons in adolescent dogfish, scyliorhinus caniculus (l.), with reference to ultrastructure of early stages, histogenesis of the renal countercurrent system, and nephron segmentation in marine elasmobranchs. | light and electron microscopy of the excretory kidney of adolescent dogfish, scyliorhinus caniculus (l.), revealed immature and mature nephrons as well as four developmental stages of nephrons. at stage i the nephron was characterized by a condensed mass of mesenchymal cells in the center of several concentric layers of connective tissue. at stage ii of the nephron, the s-shaped body was an elongate cyst with a high prismatic epithelium that was connected by a developing collecting tubule with t ... | 1991 | 2058567 |
| scyliorhinin i and ii: two novel tachykinins from dogfish gut. | two peptides with tachykinin-like ability to contract longitudinal muscle from the guinea pig ileum were isolated from the intestine of the common dogfish, scyliorhinus caniculus. the amino acid sequence of scyliorhinin i was established as ala-lys-phe-asp-lys-phe-tyr-gly-leu-met-nh2 and this peptide cross-reacted with antisera directed against the c-terminal region fo substance p. the amino acid sequence of scyliorhinin ii was established as ser-pro-ser-asn-ser-lys-cys-pro-asp-gly-pro-asp-cys-p ... | 1986 | 2422058 |
| a novel vasoactive intestinal peptide (vip) from elasmobranch intestine has full affinity for mammalian pancreatic vip receptors. | a peptide that cross reacted with n-terminal, but not c-terminal, antisera to vasoactive intestinal peptide (vip) was isolated from extracts of intestine from the dogfish scyliorhinus canicula. microsequence analysis gave the structure his-ser-asp-ala-val-phe-thr-asp-asn-tyr-ser-arg-ile-arg-lys-gln-met-ala-val-lys - lys-tyr-ile-asn-ser-leu-leu-ala-nh2. c-terminal amidation was determined by hplc analysis of phenylthiocarbamyl amino acid derivatives after carboxypeptidase y digestion. the peptide ... | 1987 | 2441759 |
| factors affecting the secretory dynamics of 1 alpha-hydroxycorticosterone in the dogfish, scyliorhinus canicula. | the secretory dynamics (plasma concentrations, metabolic clearance rates (mcr), and blood production rates (bpr] of 1 alpha-hydroxycorticosterone (1 alpha oh-b) were examined in scyliorhinus canicula under a number of experimental conditions. both hypophysectomy and injections of dexamethasone significantly reduced the plasma concentrations of 1 alpha oh-b, although significant, measurable amounts remained. in hypophysectomized animals mcr increased and bpr decreased. intravenous administration ... | 1985 | 2991077 |
| the location of cardiac vagal preganglionic neurones in the brain stem of the dogfish scyliorhinus canicula. | the locations, within the brain stem, of vagal efferent preganglionic neurones with axons in the two pairs of cardiac vagal rami of the dogfish have been defined by the retrograde intra-axonal transport of horseradish peroxidase (hrp). hrp was applied to the cardiac rami in one of two ways: either as crystals placed on the cut central end of the nerve or as a dried concentrated solution administered into the nerve on the tip of a fine pin. no difference was observed in the number of labelled cel ... | 1985 | 2415654 |
| perfusion-secretion relationships in the isolated elasmobranch rectal gland. | perfusion and sodium secretion parameters were measured in the isolated rectal gland of scyliorhinus canicula l. perfused at in vivo pressures, and the effect of stimulation of secretory activity by cyclic amp and theophylline on these parameters was determined. stimulation resulted in large increases in secretion flow rate, percentage extraction of sodium from the perfusing fluid, and arteriovenous sodium concentration difference, but did not affect perfusion flow rate or the sodium concentrati ... | 1986 | 3020149 |
| leukotriene b4 induces enhanced migration of fish leucocytes in vitro. | leukotriene b4 (ltb4) was found to induce enhanced migration of the eosinophilic g1 granulocyte of the dogfish scyliorhinus canicula in the migration under agarose assay. higher levels of ltb4, however, were required to produce this effect than with mammalian neutrophils under similar conditions. it is postulated that this may be due to the dogfish granulocytes possessing fewer receptors for ltb4 than their mammalian counterparts. the eosinophilic g3 granulocyte was also tested using the same as ... | 1986 | 3026961 |
| characterization of a chymosin-like pepsin from the dogfish scyliorhinus canicula. | 1. pepsin ii extracted from the gastric mucosa of scyliorhinus canicula has been characterized and compared to calf chymosin. 2. the kcat and km of the dogfish enzyme for the synthetic hexapeptide leu-ser-phe(no2)-nle-ala-leu-ome have been determined. the kcat/km ratio is close to that of calf chymosin. its milk-clotting efficiency is however 21-fold lower than that of calf chymosin. 3. the proteolytic activity against haemoglobin is optimal at ph 2.5. it clots the milk up to ph 6.8. 4. the dogf ... | 1987 | 3123128 |
| gill metabolism after chronic subacute zinc treatments. | atp and lactate concentration of the gill tissue of scyliorhinus canicula were determined after short-term and long-term subacute zinc exposure. increase of lactate and decrease of atp levels were detected after short-term exposure, while no significant changes were observed after long-term treatment, suggesting a recovery process or an activation of compensatory mechanisms. | 1985 | 2938419 |
| effects on dogfish haematology and liver composition after acute copper exposure. | 1. dogfish scyliorhinus canicula was subjected to experimental acute copper pollution. at the lowest concentration no changes were recorded on haemoglobin levels whilst decreases of the erythrocyte number and haematocrit was found. 2. at higher concentrations near to the lethal doses, a general reduction of all blood parameters was observed. 3. liver composition (protein, glycogen and lipid levels) was not affected by any copper concentration, over the duration of the experiments. 4. results are ... | 1987 | 2888579 |