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differential effects of thyroxine on metabolic enzymes and other macromolecules in a freshwater teleost.the effects of thyroxine (t(4)) on citrate synthase (cs), glucose 6-phosphate dehydrogenase (g6-pdh), lactate dehydrogenase (ldh), dna, rna, and protein of various tissues were studied to elucidate the hormonal control of metabolism in a freshwater catfish, clarias batrachus. t(4) did not produce any significant effect on dna content of the fish. the cs, rna, and protein contents of brain, liver, and skeletal muscle of the fish exposed to thiourea for 28 days decreased approximately 50-58% as co ...200312658717
two morphological types of pineal window in catfish in relation to photophase and scotophase activity: a morphological and experimental study.the pineal window is a transparent/translucent pineal covering on the dorsal surface of the cranium of certain fishes and is associated with light reactions of fish. in the present study, catfish species clarias batrachus, heteropneustes fossilis, mystus vittatus, m. seenghala, and m. cavassius were examined for the type of pineal window present. two morphologically different types of pineal window were found: an opaque-looking pineal window in c. batrachus and h. fossilis and a translucent type ...200312506400
ultra-structural observations on the lymphoid organs of the freshwater catfish, clarias batrachus (linnaeus).light microscopic and ultra-structural studies of the lymphoid tissues such as blood immunocytes, spleen and pronephros of the freshwater catfish, clarias batrachus, were carried out. the peripheral blood showed nucleated erythrocytes, total leucocytic count (tlc) more than that observed in mammalian blood and leucocytes with morphological appearance similar to the mammalian white blood cells (wbcs). the spleen and pronephros showed presence of numerous lymphocytes, monocytes and nucleated red b ...200315259602
cyclic amp level and phosphodiesterase activity during 17alpha,20beta-dihydroxy-4-pregnen-3-one induction and theophylline inhibition of oocyte maturation in the catfish, clarias batrachus.this study directly tested the hypothesis that the induction of oocyte maturation in the catfish clarias batrachus is followed by a transient decrease in oocyte cyclic amp (camp) level that is due to an increase in phosphodiesterase (pde) activity. further, the pde inhibitor theophylline was used to investigate the possible role of pde in the maturation-inducing action of 17alpha,20beta-dihydroxy-4-pregnen-3-one (17alpha,20beta-dp), the physiological maturation-inducing steroid of this catfish s ...200312547256
fenvalerate-induced macromolecular changes in the catfish, clarias batrachus.the effects of sublethal concentration of fenvalerate on dna, rna, rna/dna ratio and protein contents were estimated in gill and kidney tissues of an air breathing fish, clarias batrachus. fenvalerate reduced the dna content in gill, whereas it did not produce any significant effect on dna in kidney. this tissue-specific change in dna content may be due to differential effects of fenvalerate or its metabolite(s) on synthesis and/degradation of dna in gill and kidney cells of the fish. rna and pr ...200212602849
role of amino acid metabolism in an air-breathing catfish, clarias batrachus in response to exposure to a high concentration of exogenous ammonia.the air-breathing ureogenic walking catfish (clarias batrachus) faces various environmental constraints throughout the year leading to the problem of accumulation of toxic ammonia. in the present study, the possible role of conversion of accumulated ammonia to various non-essential free amino acids (faas) was tested in this fish under hyper-ammonia stress caused by exposing the fish at 25 mm nh(4)cl for 7 days. significant accumulation of ammonia of approximately two- to threefold was observed i ...200212381386
role of cyclic amp-dependent protein kinase in oocyte maturation of the catfish, clarias batrachus.the results of the present study demonstrate the probable involvement of adenosine 3',5'-cyclic monophosphate (camp)-dependent protein kinase (pka) in the regulation of oocyte maturation in the catfish, clarias batrachus. a decrease in total pka activity with a concomitant increase in the percentage of germinal vesicle breakdown (gvbd) was found in oocytes treated with different doses of n-(2-[p-bromocinnamylamino]ethyl)-5-isoquinoline sulfonamide (h-89), a selective, potent inhibitor of pka and ...200212115942
induction of micronuclei and erythrocyte alterations in the catfish clarias batrachus by 2,4-dichlorophenoxyacetic acid and butachlor.the micronucleus test (mnt) in fish erythrocytes has increasingly been used to detect the genotoxic effects of environmental mutagens and its frequency is considered to reflect the genotoxic damage to cells, mainly the chromosomes. besides, morphologically altered erythrocyte is taken as an index of cytotoxicity. both parameters were used in the present study by two herbicides, 2,4-dichlorophenoxyacetic acid (2,4-d, in 25, 50 and 75ppm concentrations) and 2-chloro-2,6-diethyl-n-(butoxymethyl) ac ...200212113764
effect of alkalinity (ph 10) on ureogenesis in the air-breathing walking catfish, clarias batrachus.exposure of fish to alkaline conditions inhibits the rate of ammonia excretion, leading to ammonia accumulation and toxicity. the purpose of this study was to determine the role of ureogenesis via the urea cycle, to avoid the accumulation of ammonia to a toxic level during chronic exposure to alkaline conditions, for the air-breathing walking catfish, clarias batrachus, where a full complement of urea cycle enzyme activity has been documented. the walking catfish can survive in water with a ph u ...200212020651
carbofuran toxicity on total lipids and free fatty acids in air breathing fish during exposure and cessation of exposure--in vivo.clarias batrachus, fish were exposed to sublethal concentration of commercial carbofuran for 144 hr. after 144 hr of exposure period, fish were transferred to fresh water and kept in the same for 144 hr in order to study the effect of carbofuran after cessation of intoxication. total lipids and free fatty acids were determined in liver, muscle kidney and ovary at an interval of 24, 72 and 144 hr during exposure and after the release into toxicant free water. total lipids increased in all the tis ...200111554484
seasonal changes in beta-endorphin-like immunoreactivity in the olfactory system of the female catfish, clarias batrachus (linn).in the olfactory system of the catfish clarias batrachus, beta-endorphin-like immunoreactivity was seen in several olfactory receptor neurons (orn) and their fiber projections extending caudally over the olfactory nerve to the olfactory bulb (ob). with beta-endorphin-like immunoreactivity as a cellular marker, the olfactory system in the female fish was investigated at different stages of its annual reproductive cycle. the reproductive cycle of the fish is divisible into four distinct phases: pr ...200111482933
effect of trypanosomes infection on blood ascorbic acid and serum aldolase levels on the fresh water fishes, clarias batrachus and heteropneustus fossilis.the trypanosomes presence has been found to decrease blood ascorbic acid levels in fishes, clarias batrachus and heteropneustus fossilis by 55.7% and 54.70% respectively. the infection also showed significant increase in serum aldolase level of three fishes by 50.19% and 48.06% respectively.200111480356
castration-induced hyperactivity of seminal vesicle in the catfish clarias batrachus: a case of paradox and blockade by antiandrogen (cyproterone acetate) treatment.castration of the catfish clarias batrachus in late preparatory-early prespawning phase (april-may) caused time-dependent stimulatory effect on morphology, weight, and in the concentrations of biochemical correlates, such as total proteins, fructose, hexosamines and sialic acid in the seminal vesicle (sv). the peak changes were noticed on week 4 of castration. the hyperactivity was related to augmented production of testosterone by the sv of castrates with the levels significantly high from week ...200111396845
effect of pesticides carbaryl and phorate on serum cholesterol level in fish, clarias batrachus (linn).freshwater edible catfish clarias batrachus (linn.) was treated with sublethal concentration of two different groups of pesticides- carbaryl, a carbamate and phorate, an organophosphate for 24 ,72 ,120 and 168 h. the disorders of lipid metabolism were observed in serum. cholesterol levels in the serum decreased significantly throughout the exposure period with both the pesticides. these results indicate one significant manifestation of the toxic response from the fish under the stress of pestici ...200112017268
glucagon-like immunoreactivity in the forebrain and pituitary of the teleost, clarias batrachus (linn.).the organization of glucagon-like immunoreactivity (gli) in the olfactory system, forebrain, and pituitary was investigated in the teleost clarias batrachus. weak to moderate gli was seen in some olfactory receptor neurons and basal cells of the olfactory epithelium. intense gli was seen in the olfactory nerve fascicles that ran caudally to the bulb, spread over in the olfactory nerve layer, and profusely branched in the glomerular layer to form tufts organized as spherical neuropils; some of th ...200111161767
periovulatory changes in catfish ovarian oestradiol-17beta, oestrogen-2-hydroxylase and catechol-o-methyltransferase during gnrh analogue-induced ovulation and in vitro induction of oocyte maturation by catecholoestrogens.in the catfish heteropneustes fossilis and clarias batrachus, ovarian oestrogen-2-hydroxylase (oe-2-h) activity increased significantly at 8 h after the injection of an ovulatory dose (0.15 microg/g body weight) of a mammalian gnrh analogue ([d -ala(6)-pro(9)]-lhrh ethylamide) and was restored to the 0 h (control) level after egg-stripping at 16 h. on the other hand, ovarian oestradiol-17beta (oe2) level and catechol-o-methyltransferase (comt) activity decreased significantly at 8 h. while the o ...200111182761
effects of ovine lh, gh and prolactin, and testosterone on serum testosterone and estradiol-17 beta levels, and seminal vesicle and testicular activity in the catfish clarias batrachus (l.).intraperitoneal administrations of testosterone (0.5 microgram/g body wt), and ovine lh (1.0 microgram/g body wt), gh (5 micrograms/g body wt) and prolactin (10 micrograms/g body wt) daily for 7 days during early prespawning phase (may) in c. batrachus produced varied effects on seminal vesicle (svsi) and testicular (gsi) weights and biochemical correlates. testosterone and lh treatments significantly increased serum testosterone level and concentrations of total proteins, fructose, hexosamines ...200111349526
role of two plasma vitellogenins from indian major carp (cirrhinus mrigala) in catfish (clarias batrachus) vitellogenesis.complete vitellogenesis (synthesis and incorporation of vitellogenin, vg) in the female catfish, clarias batrachus, during different reproductive phases (preparatory, prespawning, and postspawning) of its annual ovarian cycle is induced by administering heterologous vg (semipurified; ult-i and purified; ha-i and ha-ii) isolated from the indian major carp, mrigal (cirrhinus mrigala). during the prespawning period, ult-i, which contains both ha-i and ha-ii, showed a dose-dependent response in rela ...200111703069
pesticide induced alterations of non-protein nitrogenous constituents in the serum of a fresh water cat fish, clarias batrachus (linn.).a freshwater cat fish was exposed to sublethal concentrations of two pesticides--carbaryl, a carbamate and phorate, an organophosphorus pesticide for 24, 72, 120 and 168 hr. the alterations in the serum profile of non protein nitrogen compounds demonstrated an increase in urea, uric acid and creatinine throughout the experimental period.200011324161
role of thyroidal and testicular hormones in regulation of tissue respiration in male air-breathing fish, clarias batrachus (linn.).in vivo and in vitro effects of thyroidal hormones (mit, dit, t3, t4), propyl thiouracil (ptu), testosterone and cyproterone acetate were studied on the rate of tissue (liver, muscle, kidney and brain) respiration of adult male c. batrachus during winter and summer/rainy seasons. monoiodotyrosine (mit) and diiodothyrosine (dit) increased the respiratory rate in a dose-dependent and temperature-independent manner. triiodothyronine (t3) and thyroxine (t4) stimulated tissue respiration during summe ...200011215315
role of l-thyroxine, hydrocortisone and progesterone in regulation of blood volume in a fresh-water air-breathing fish, clarias batrachus (linn.).effect of hormones on the blood volume of clarias batrachus were ascertained and it was observed l-thyroxine and progesterone decrease, while hydrocortisone increases the total and relative blood volumes. the ratio of plasma to corpuscular volume is increased by the intraperitoneal injection of l-thyroxine, hydrocortisone and progesterone (higher dose only), thus indicating the regulation of blood volume under the complex control of homeostasis.200085575
beta-adrenoceptor antagonists reinitiate meiotic maturation in clarias batrachus oocytes.effects of beta-adrenoceptor antagonists propranolol and alprenolol in the oocyte maturation of the catfish (clarias batrachus) were investigated under in vitro. cyclic amp (camp) levels were also measured in the control, propranolol and phosphodiesterase (pde) inhibitor treated oocytes. when full-grown folliculated oocytes were cultured in vitro in the presence of different concentrations of propranolol or alprenolol, both the substances induced germinal vesicle breakdown (gvbd) in a dose-depen ...200010989342
methallibure inhibition of testicular and seminal vesicle activity in catfish, clarias batrachus (linn.): a study correlating changes in serum sex steroid profiles.the administration of methallibure (2 microg/g bw, daily for 15 days) in clarias batrachus in prespawning phase (may-june) resulted in decreased weights of seminal vesicle (sv) and testis, and reductions in the concentrations of total proteins, fructose, hexosamines, and sialic acid in sv and testis. the inhibitory changes can be attributed to impairment of steroidogenesis, serum levels of testosterone and estradiol -17beta decreased significantly. withdrawal of methallibure treatment for 7 and ...200010866360
beta-endorphin and gonadotropin-releasing hormone in the forebrain and pituitary of the female catfish, clarias batrachus: double-immunolabeling study.the role of beta-endorphin in modulating the gonadotropic action of gonadotropin-releasing hormone (gnrh) is well established in mammals. although the information from teleosts also suggests that endogenous opioids modulate gnrh secretion and influence gonadotropic hormone release, the anatomical substrate in which opiate peptides and gnrh may interact has not been studied. herein we describe the mammalian gnrh- and beta-endorphin-like immunoreactivities in the olfactory system, forebrain, and p ...200010753565
subcommissural organ-reissner's fiber complex of the teleost clarias batrachus responds to gaba treatment.subcommissural organ (sco) is a highly specialized ependymal gland located in the roof of the third ventricle. the secretory products of the sco, which condense to form reissner's fiber (rf), were recently found to cross-react with the anti-calcitonin antibody. to understand the mechanisms regulating the formation of the rf and the possible function of these discrete structures, we studied the response of the sco-rf complex to intracranially administered gaba, using immunocytochemical labeling w ...200010678760
changes in free amino acid synthesis in the perfused liver of an air-breathing walking catfish, clarias batrachus infused with ammonium chloride: a strategy to adapt under hyperammonia stress.the changes in the free amino acid (faa) levels, the rate of efflux of faas from the perfused liver, and the activity of some enzymes related to amino acid metabolism such as glutamate dehydrogenase (gdh, both reductive amination and oxidative deamination), glutamine synthetase (gs), aspartate aminotransferase (ast), and alanine aminotransferase (alt) were studied in the liver of a freshwater air-breathing teleost, the walking catfish, clarias batrachus, perfused with 5 and 10 mm nh(4)cl. the le ...200010607365
cyclic amp-mediated control of oocyte maturation in the catfish, clarias batrachus (bloch): effects of 17 alpha,20 beta-dihydroxy-4-pregnen-3-one and phosphodiesterase inhibitors.an increase in the percentage of germinal vesicle breakdown (gvbd) with a corresponding decrease in camp was found in the oocytes which were incubated for 36 hr with different concentrations of 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (17 alpha,20 beta-dp). at its highest concentration (1 microgram/ml), 17 alpha,20 beta-dp induced 91.9 +/- 2.3% gvbd and decreased camp level to 0.8 +/- 0.1 pmol/oocyte from 2.9 +/- 0.2 pmol/oocyte (control). the two different known inhibitors of phosphodiesteras ...200011324167
pituitary-gonadal relationship in the catfish clarias batrachus (l): a study correlating gonadotrophin-ii and sex steroid dynamics.a heterologous radioimmunoassay was developed for measuring gonadotrophin-ii (gth-ii) in the catfish clarias batrachus. serum and/or pituitary levels of gth-ii showed significant annual/seasonal variations in male and female catfish, which could be correlated with both gonadosomatic index and/or serum testosterone level. gth-ii was not detected in resting phase, increased during gonadal recrudescence to peak values in late prespawning /spawning phases, and declined to low values in postspawning ...200018494596
effect of carbaryl on some biochemical constituents of the blood and liver of clarias batrachus, a fresh-water teleost.carbaryl, a carbamate pesticide, (lc50 15.08 mg/l for 96 hr, i.e. lethal concentration with 50% mortality) induced perturbations in the levels of certain biochemical components including the activities of some enzymes in the blood and liver of the fresh-water catfish, clarias batrachus exposed to sublethal concentrations (1, 2 and 4 mg/l) of the pesticide for 96 hr and 15 days. the pesticide caused a decrease in the levels of total protein and glucose with a concomitant increase in the levels of ...199910478330
scaling of some metabolic enzymes in liver of a freshwater teleost: an adaptive mechanism.the activities of mitochondrial malate dehydrogenase (mmdh) and the total mitochondrial proteins increase as a function of body mass in the freshwater catfish, clarias batrachus. it clearly indicates an increase in energy production in larger-sized individuals for various purposes including prey-predator interactions. the higher activity of lactate dehydrogenase (ldh) in larger fish may indicate more production of lactate for gluconeogenesis in the liver to meet emergency requirements of increas ...199910685503
certain pesticide-induced carbohydrate metabolic disorders in the serum of freshwater fish clarias batrachus (linn.).a freshwater edible catfish, clarias batrachus (linn.), was exposed to sublethal concentrations of two different groups of pesticides-carbaryl, a carbamate and phorate, an organophosphorus (op) pesticide-for 24, 72, 120 and 168 hours. the alterations and the disorders of carbohydrate metabolism were studied in the serum. serum glucose, alkaline phosphatase and bilirubin levels increased with both the pesticides throughout the exposure period. the results indicate that the carbohydrate metabolism ...199910418957
31p nuclear magnetic resonance studies on the phosphorus-containing metabolites of the developing embryos of a freshwater catfish, clarias batrachus (l.).: changes in the phosphorus-containing metabolites were monitored by 31p nuclear magnetic resonance in the developing embryos of clarias batrachus. phosphomonoester, yolk phosphoprotein, phosphocreatine, atp, and inorganic phosphate (pi) were consistently observed in all the developmental stages of c. batrachus. none of these phosphometabolites exhibited any significant change in their concentration up to the blastula stage, whereas distinct decrease in all except inorganic phosphate was observe ...199910383996
effect of acute exposure of the organophosphate insecticide rogor on some biochemical aspects of clarias batrachus (linnaeus).indian catfish (clarias batrachus), a common fish of commercial importance, was exposed to a sublethal concentration (1/3 of 96 h lc50 value) of rogor for periods ranging from 24 to 192 h. the changes in glycogen, lactate, lactate dehydrogenase, and glycogen phosphorylase (a, ab) contents of muscle tissue were studied. a gradual decrease in muscle glycogen and an increase in lactate contents were observed. the activity level of lactate dehydrogenase showed a sharp rise initially for 48 h followe ...19999931229
beta-endorphin-like immunoreactivity in the forebrain and pituitary of the teleost clarias batrachus (linn.).the organization of beta-endorphin-like immunoreactivity in the olfactory system, forebrain, and pituitary of the teleost clarias batrachus was investigated. immunoreactivity was prominently seen in the sensory neurons and basal cells in the olfactory epithelium and in some cells in the periphery and center (granule cells) of the olfactory bulb. immunoreactive fibers in the olfactory nerve enter the olfactory nerve layer of the olfactory bulb and branch profusely to form tufts organized as spher ...199910082632
vanadium toxicology--an assessment of general health, haematological aspects and energy response in an indian catfish clarias batrachus (linn).the pervasive occurrence of vanadium in nature and its use in various industrial processes has increased its inputs in the environment. this has prompted us to elucidate the impact of vanadium on aquatic environment, the primary body for industrial effluent discharge. the energy response of the fish, clarias batrachus, its haematological status including haemoglobin (hb), haematocrit (ht), leutocrit (lt), mean corpuscular haemoglobin (mch), mean corpuscular volume (mcv), mean corpuscular haemogl ...19989542062
characterization of mboi satellites in cirrhina mrigala and clarias batrachus (pisces).we have cloned and characterized two highly reiterated, tandemly repeated, and a+t rich mboi dna fragments, one in cirrhina mrigala (cyprinidae), with a monomer size of 266 bp, and one in clarias batrachus (clariidae), with a monomer size of 227 bp. the mboi fragment in c. mrigala is species-specific and absent in other carps, such as catla catla and labeo rohita. the mboi fragment in c. batrachus was also present in two other catfishes tested, namely clarias gariepinus and heteropneustes fossil ...19989549057
partial purification of maturation-promoting factor from catfish, clarias batrachus: identification as the histone h1 kinase and its periodic activation.maturation-promoting factor (mpf) has been demonstrated in the 100,000 g supernatant of 17 alpha, 20 beta-dihydroxy-4-pregnen-3-one (17 alpha, 20 beta-dp)-induced catfish, clarias batrachus oocytes using deae-cellulose and sephadex g-200 chromatography. partially purified mpf molecule eluted as a single peak on sephadex g-200 with molecular mass of approximately 200 kda in native page. sds-page analysis showed the presence of five proteins of 32, 34, 45, 46 and 48 kda. antibody against the pstai ...19989827048
precocious recrudescence of seminal vesicle and testis in catfish, clarias batrachus (linn.), subjected to a long photoperiod regime.the catfish c. batrachus were exposed to a long photoperiod of 14 hr light during resting--early preparatory (december-february) phases of the reproductive cycle. at 70-day sampling, both the seminal vesicle (sv) and testis registered marked stimulatory effects in comparisons to control fish maintained under approximately 10.55 l:13.45d as shown by the increased size and weight. in both the sv and testis, concentrations of total proteins, fructose, hexosamines, and sialic acid were significantly ...199810093510
fmrfamide-like immunoreactivity in the olfactory system responds to morphine treatment in the teleost clarias batrachus: involvement of opiate receptors.in view of the close relationship between the fmrf-related peptides and the central opiate-sensitive system, we investigated the effects of morphine, alone and in combination with naloxone, on the fmrfamide-like immunoreactivity in the olfactory system of the teleost, clarias batrachus. in the olfactory system of normal and untreated fish, fmrfamide-like immunoreactivity was confined to the ganglion cells and fibers of the terminal nerve; the cells in the olfactory epithelium per se or the olfac ...19989514843
calcitonin-like immunoreactivity in the subcommissural organ and reissner's fiber in the teleost clarias batrachus, frog rana tigrina and lizard calotes versicolor.in the cns of vertebrates, although the subcommissural organ (sco) has been identified as an ependymal brain gland and reissner's fiber (rf) as a condensed product of its secretion, the exact nature of the secretory substances has remained elusive. in the present study, immunocytochemical application of polyclonal antibodies against calcitonin revealed intense immunoreactivity in the cells, cell processes and cerebrospinal spinal fluid (csf)-contacting apical terminals of the columnar ependymal ...19979098563
regulation of membrane lipid bilayer structure during seasonal variation: a study on the brain membranes of clarias batrachus.(1) a significant seasonal variation in the membrane fluidity (as sensed by dph-fluorescence polarization), membrane lipid components (phospholipid and neutral lipid), fatty acid composition of membrane phospholipid (phosphatidylcholine, phosphatidylethanolamine and sphingomyelin), positional distribution of fatty acids at sn-1 and sn-2 position of phosphatidyl-choline and -ethanolamine is noticed in the brain membranes (myelin, synaptosomes, and mitochondria) of a tropical air breathing teleost ...19979030213
effects of administration of testosterone on seminal vesicle activity in the catfish clarias batrachus during preparatory phase: a study correlating changes in testis and serum sex steroid levels.in the catfish clarias batrachus administration of testosterone (0.25, 0.5 and 1.0 microgram/g bw for 30 days) during the preparatory phase increased significantly gonadosomatic index (gsi), seminal vesicle-somatic index (sv-si) and concentrations of proteins, fructose, hexosamines, and sialic acid in the sv and testis in a dose-dependent manner. these stimulatory effects could be correlated positively with the increase of serum testosterone level. serum estradiol-17 beta was also significantly ...19979847455
direct mutagenicity of the polycylic aromatic hydrocarbon-containing fraction of smoked and charcoal-broiled foods treated with nitrite in acid solution.the polycyclic aromatic hydrocarbons (pah) containing fractions of smoked and charcoal-broiled foods, namely, sheat fish (kytopterus apogon), mimrow (crossocheilus reba), freshwater catfish (clarias batrachus), chicken wings, rice pork sausage and pork, in addition to naphthalene, acenaphthene, anthracene, phenanthrene, fluoranthene, pyrene, benz[a]anthracene, naphthacene, benzo[a]pyrene, benzo[e]pyrene, 9,10-dimethyl-1,2-benzanthracene, dibenz[ah]anthracene, benzo[ghi]perylene and coronene, wer ...19979146734
impact of endosulfan on cytoplasmic and mitochondrial liver malate dehydrogenase from the freshwater catfish (clarias batrachus).the impact of a sublethal concentration of an organochlorine pesticide endosulfan on the activity, specific activity, electrophoretic patterns and kinetic properties of crude and purified forms of cytoplasmic malate dehydrogenase (cmdh) and mitochondrial malate dehydrogenase (mmdh) was evaluated in the liver of the freshwater catfish, clarias batrachus. the endosulfan reduced significantly the activity and the specific activity of cmdh and mmdh, but had no effect on total cytoplasmic and mitocho ...19979185323
the in vitro effects of forskolin, ibmx and cyanoketone on meiotic maturation in follicle-enclosed catfish (clarias batrachus) oocytes.the effects of an adenylate cyclase activator (forskolin, fk), phosphodiesterase inhibitor (3-isobutyl-l-methyl-xanthine, ibmx) and an inhibitor of steroidogenesis (cyanoketone, ck) on germinal vesicle breakdown (gvbd) in the catfish (clarias batrachus) were investigated in vitro. in most of the experiments gvbd was induced by using 1 microgram/ml 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (17 alpha,20 beta-dp), which is the maturation-inducing steroid (mis) for this species. adenosine 3':5'-cyc ...19969568358
alterations in protein metabolism of muscle tissue in the fish clarias batrachus (linn) by commercial grade dimethoate. 19968661902
identification and characterization of maturation-promoting factor from catfish,clarias batrachus.maturation-promoting factor (mpf) extracted from maturing oocytes of catfishes (clarias batrachus andheteropneustes fossilis) and carp (labeo rohita) induces 100% germinal vesicle breakdown (gvbd) when microinjected intoclarias immature unstimulated oocytes. the presence of a similar mpf activity has also been demonstrated in the active fractions collected after superose 12. sds-page analyses of cytosolic extracts (ce) prepared from immature and mature oocytes revealed the presence of 34- and 46 ...199624194144
lead induced thyroid dysfunction and lipid peroxidation in the fish clarias batrachus with special reference to hepatic type i-5'-monodeiodinase activity. 19968645925
activation of hypothalamic neurons by intraovarian pressure signals in a teleost fish, clarias batrachus: role of mechanosensitive channels.application of intraovarian pressure is known to trigger profound cytomorphological changes in the neurosecretory cells of nucleus preopticus in the teleost clarias batrachus. these findings indicate the presence of stretch receptors in the ovaries, perhaps equipped with mechanosensitive channels that transduce the stretch signals to be transmitted to the brain. to test the occurrence of the mechanosensitive channels in the ovaries, we administered a range of pharmacological agents (lignocaine, ...19969156780
presence of maturation-promoting factor in 17α,20β-dihydroxy-4-pregnen-3-one-induced oocytes of catfish, clarias batrachus.full-grown immature clarias batrachus oocytes respond in vitro to exogenous 17α,20β-dihydroxy-4-preg-nen-3-one ( 17α,20β-dp) by undergoing germinal vesicle breakdown (gvbd). cytosolic extract (ce) prepared from 17α,20β-dp-induced oocytes has been shown to produce similar effect when microinjected into unstimulated immature oocytes of the same fish. a dose of ∼ 50 nl is enough to cause 100% gvbd after 4 h. maturation-promoting factor was investigated from 17α,20β-dp-induced, immature and cyclohex ...199524197646
microcirculation of gills and accessory respiratory organs of the walking catfish clarias batrachus.an ability to extract oxygen directly from the atmosphere enables air-breathing fish to survive otherwise debilitating hypoxic environments. addition of accessory respiratory organs (aro) necessitates changes in both the general circulatory system and the microcirculation of the respiratory epithelia. understanding these modifications provides information on the efficiency of gas exchange organs as well as an indication of the evolutionary processes associated with adaptation to terrestrial habi ...19957573985
carbohydrate metabolism in hepatic tissue of freshwater catfish clarias batrachus l. during dimethoate exposure.clarias batrachus l., a freshwater catfish of commercial importance, was exposed to a sublethal concentration of dimethoate (rogor). the acute effect of dimethoate on some aspects of carbohydrate metabolism of hepatic tissue was studied after 1, 2, 4 and 8 days. the glycogen content was depleted, whereas the lactate level was elevated throughout the experimental period and an increase in lactate dehydrogenase was observed. the activity levels of glycogen phosphorylase a and ab in the hepatic tis ...19957759027
in vivo toxicity of dimethoate on proteins and transaminases in the liver tissue of fresh water fish clarias batrachus (linn). 19957749268
changes in lipid profiles and 32p-uptake into phosphoprotein (vitellogenin) content of the ovary and liver in the female catfish, clarias batrachus, exposed to mercury.toxic effects of selected sublethal concentrations of mercuric chloride (hgcl2, 0.05 mg.l-1), methylmercuric chloride (ch3hgcl, 0.04 mg.l-1) and emisan 6 (an organic mercurial fungicide, 0.5 mg.l-1) on levels of lipids (total lipids-tl, phospholipids-pl, free cholesterol-fc; esterified cholesterol-ec and free fatty acids-ffa), and uptake of 32p into phosphoprotein fraction of the ovary and liver are reported in clarias batrachus exposed for 45, 90 and 180 days from february to july (preparatory ...19957605598
sublethal effect of mercury and lead on monoamine oxidase in different regions of the brain in three freshwater teleosts.effect of mercury and lead at 24 and 48 h was investigated on monoamine oxidase (mao) activity in different regions of the brain (telencephalon, cerebellum, diencephalon and medulla oblongata) in labeo rohita, ham., clarias batrachus, l. and channa punctatus, bloch. highest rise in mao activity was recorded in telencephalon with mercury followed by lead. maximum variations in the level of mao activity in different regions of the brain were recorded at 24 h exposure. the observed alterations were ...19958606989
alterations in enzymes in an indian catfish, clarias batrachus (linn.), exposed to vanadium. 19957742637
in vitro effects of divalent metal ions and metabolic modulators on purified glutamine synthetase from brain of teleostean fish.the purified brain glutamine synthetase of a teleostean fish, clarias batrachus has been examined under the influence of divalent metal ions activation and in vitro studies using different amino acids and metabolic modulators. all observations of the enzyme activity are based on transferase reaction at optimum temperature and ph. the enzyme exhibits an absolute requirement for mn2+ (most potent) mg2+ and co2+. the activity is markedly inhibited by leucine, asparagine, isoleucine, carbamyl phosph ...19951382667
intracranial metyrapone stimulates crf-acth axis in the teleost, clarias batrachus: possible role of neurosteroids.intracranial administration of metyrapone, a blocker of the enzyme 11-beta-hydroxylase, which is essential for the biosynthesis of corticosteroids, resulted in profound stimulation of the nucleus preopticus and the crf-acth axis in the teleost, clarias batrachus. it is suggested that the putative blockade of the neurosteroid biosynthesis following metyrapone might be responsible for this action. the present study for the first time uncovers the possibility of inhibitory regulation of the crf-act ...19947865753
effects of short-term exposure to methylmercury chloride and its withdrawal on serum levels of thyroid hormones in the catfish clarias batrachus. 19948069068
control of melanosome movements in isolated skin melanophores of a catfish clarias batrachus (linn.).adrenergic and cholinergic receptors have been studied in isolated skin melanophores of a catfish clarias batrachus. catecholamines induced a strong aggregatory effect on the melanophores. melanosome aggregation induced by adrenaline and noradrenaline was partially blocked by alpha adrenergic receptor blockers and a beta receptor blocker. cholinomimetic drugs aroused a significant dispersion of melanophroes. atropine effectively blocked the dispersal, responses of melanophores to acetylcholine a ...19947814079
molecular weight of cytoplasmic malate dehydrogenase, mitochondrial malate dehydrogenase and lactate dehydrogenase of a freshwater catfish.the multiple molecular forms of cytoplasmic malate dehydrogenase (cmdh), mitochondrial malate dehydrogenase (mmdh) and lactate dehydrogenase (ldh) were studied in the liver and skeletal muscle of the freshwater catfish, clarias batrachus. there were two electrophoretically distinguishable bands (aa and bb) of cmdh and mmdh which suggests that they are apparently encoded at two gene loci (a and b) in both the tissues. however, the presence of a single band (ldh-1) of ldh in liver and double bands ...19947946007
effect of cadmium chloride on the pituitary, thyroid and gonads in the catfish, clarias batrachus (linn.).the effect of cadmium chloride on the pituitary acth cells, gonadotropin- and thyrotropin-secreting cells, thyroid gland and gonads of the catfish, clarias batrachus was investigated. exposure to cadmium chloride caused a significant increase in the acth cell nuclear indices at day 7, 14 and 28, whereas the thyrotropin- and gonadotropin-secreting cells showed inactivation and accumulation of secretary products. the epithelial height of the thyroid follicles was also significantly reduced (p < 0. ...19947819608
effect of fertilizer diammonium phosphate on liver, kidney and muscle 5'-nucleotidase activity of fresh water teleost fish clarias batrachus.the toxic effect of fertilizer diammonium phosphate resulted in alterations of 5'-nucleotidase activity of tissues--liver, kidney and muscles of fish c. batrachus at varying intervals and exposures. alterations in 5'-nucleotidase activity of body organs gave an idea of the toxicity caused by the fertilizer. thus the enzyme 5'-nucleotidase can be used to monitor the pollution in aquatic ecosystem.19938198754
hypophysiotropic neurons in the hypothalamus of the catfish clarias batrachus: a cobaltous lysine and hrp study.seven hypothalamic nuclei and several isolated perikarya that send projections to the pituitary gland were identified following administration of cobaltous lysine or horseradish peroxidase (hrp) to severed hypophysial stalks of previously hypophysectomized catfish, clarias batrachus. retrogradely labelled neurons were identified in the nucleus preopticus periventricularis, suprachiasmatic nucleus, paraventricular and supraoptic divisions of the magnocellular nucleus preopticus (npo) and nucleus ...19938324622
antibody dependent haemolysin, complement and opsonin in sera of a major carp, cirrhina mrigala and catfish, clarias batrachus and heteropneustes fossilis.the present communication is a continuation of our earlier study on the natural serum haemagglutinin/lectins of cirrhina mrigala, clarias batrachus and heteropneustes fossilis. sera of cirrhina mrigala, belonging to the major carp family, could not only agglutinate heterologous rabbit erythrocytes, but also lyse them spontaneously. this lysis of rabbit rbc by cirrhina mrigala sera was calcium ion dependent and heat sensitive, indicating thereby that the haemolysis was mediated by the fish serum ...19938281746
comparison of the sublethal effect of mercury and lead on visceral dehydrogenase system in three inland teleosts.the sublethal effect of mercury and lead was investigated on visceral (liver, muscle, gill, kidney and brain) succinic, malic and lactic dehydrogenases in labeo rohita, clarias batrachus and chana punctatus in acute experiments. the highest decrease of succinic, malic and lactic dehydrogenases was recorded in the hepatic tissue in comparison to muscle, brain, kidney and gill. this decrease was greater in l. rohita than in c. batrachus or in c. punctatus. mercury was more effective than lead. mar ...19938329378
observations on the function of mucous cells in the epidermis of the cat-fish clarias batrachus exposed to sodium dodecyl sulfate.response of mucous cells, in the epidermis of the catfish clarias batrachus, to a sublethal concentration of sodium dodecyl sulfate was studied and correlated with the alteration in the status of their secretory activity after different durations of the treatment. at 4h, 8h, 24h, 48h and 72h of the detergent treatment, most mucous cells attained voluminous dimensions and appeared closely approximating to or even overlapping the adjacent ones. at 12h, 36h, and 60h, in contrast, the mucous cells a ...19938397895
thyroid physiology impairment by malathion in the freshwater catfish clarias batrachus.effects of malathion on serum and glandular thyroxine (t4), triiodothyronine (t3), the t3/t4 ratio, peroxidase activity, and extrathyroidal conversion of t4 to t3 have been studied in the freshwater catfish clarias batrachus during the prespawning and spawning phases of its annual reproductive cycle. malathion inhibited t4 secretion in the kidney, but accelerated t4 synthesis in the pharyngeal thyroid. this pesticide also inhibited the extrathyroidal conversion of t4 to t3 in serum during both t ...19921385075
oocyte maturation in clarias batrachus: in vitro effect of various gonadotropins and homologous pituitary homogenate.the effects of five different gonadotropins and homologous pituitary homogenate (hp) on germinal vesicle breakdown (gvbd) were investigated in vitro using folliculated oocytes of clarias batrachus. among all the gonadotropins, salmon gonadotropin (sg-g100) was the most potent in vitro inducer of oocyte maturation. at concentrations of 1, 0.1, 0.01 and 0.001 microgram/ml it induced 86.98 +/- 2.71, 68.74 +/- 2.85, 44.56 +/- 1.75 and 25.90 +/- 2.36% gvbd. next to sg-g100 in inducing gvbd was lutein ...19921512031
effect of endosulfan (thiodan) on vitellogenesis and its modulation by different hormones in the vitellogenic catfish clarias batrachus.this programme was planned in order to study the reproductive dysfunction caused by endosulfan in the fish clarias batrachus with special reference to vitellogenesis. vitellogenin was measured by radioimmunoassay. endosulfan caused a drastic reduction in the plasma vitellogenin which was partially reversed by estradiol-17 beta (e2) in intact and ovariectomized fish. hormones in combination were more effective than any single hormone in overcoming the impact of endosulfan. triiodothyronine (t3), ...19921455428
effect of urea exposure on the hematological parameters of clarias batrachus. 19921280582
relative toxicity of aldrin, fenvalerate, captan and diazinon to the freshwater food-fish, clarias batrachus.the median lethal concentrations (lc50s) of aldrin, fenvalerate, captan and diazinon were determined for clarias batrachus by trimmed spearman-karber method. the potency ratios of toxicity among them were analysed by parallel-line bioassay with quantal responses. the lc50s for 40 day of exposure of aldrin, fenvalerate, captan and diazinon were 0.00036, 0.0094, 0.5473 and 2.4186 ppm respectively. these values were lower than those obtained for an exposure of 96 hour. it shows the greater toxicity ...19921586464
fmrfamide-like immunoreactive nervus terminalis innervation to the pituitary in the catfish, clarias batrachus (linn.): demonstration by lesion and immunocytochemical techniques.certain thick fmrfamide-like immunoreactive fibers arising from the ganglion cells of nervus terminalis in the olfactory bulb of clarias batrachus can be traced centripetally through the medial olfactory tract, telencephalon, lateral preoptic area, tuberal area, and hypothalamohypophysial tract to the pituitary. following 6 days of bilateral olfactory tract transection, the immunoreactivity in the thick fibers, caudal to the lesion site, was partially eliminated, whereas after 10 and 14 days, it ...19921348715
oocyte maturation inclarias batrachus. iii. purification and characterization of maturation-inducing steroid.maturation-inducing steroid (mis) in the indian female catfish,clarias batrachus, was purified and characterized from the incubation medium in which fully grown but immature folliculated oocytes were incubated with salmon gonadotropin (sg-g100) for 36 h. maturation-inducing (mi) activity of residues obtained at various steps of extraction and purification was assessed byin vitro germinal vesicle breakdown (gvbd) assay using folliculated oocytes ofc. batrachus. the post incubation medium was extr ...199224213827
circadian variations in circulating plasma sex steroids in female catfish, clarias batrachus (linn.).estradiol (e2) and 17 alpha-hydroxyprogesterone (17 alpha-ohp) levels exhibited significant circadian rhythms in the prespawning phase of the reproductive cycle. pattern of rhythm was unimodal. whereas, in the spawning phase e2 levels did not show significant fluctuations in their daily cycle whereas 17 alpha-ohp levels showed significant rhythm (p less than 0.001). amplitude of rhythm of e2 was greater in prespawning phase while 17 alpha-ohp showed greater amplitude in spawning phase.19911794871
changes in adrenocortical-pituitary activity in the catfish, clarias batrachus (l.), after mercury treatment.the toxic effects of mercuric chloride (hgcl2), emisan 6 (a methoxy-ethyl mercury fungicide), and methyl mercuric chloride (ch3hgcl) on the adrenocortical-pituitary activity of the catfish were investigated after 45, 90, and 180 days of exposure. the adrenocortical cells were highly stimulated in the 90-day hgcl2 group and became hyperplastic in the 180-day group. these cells were active in the 90-day emisan 6 group, with the infiltration of lymphocytes and fibrosis in the 180-day group. in the ...19911914994
ammonia metabolism in freshwater teleost, clarias batrachus (linn.) on exposure to trichlorfon. 19912039871
cytoarchitectonic pattern of the hypothalamus in the catfish, clarias batrachus (linn.).the hypothalamus of the catfish, clarias batrachus has been investigated to reveal the organization of various parvocellular (aldehyde fuchsin-negative) nuclear complexes and to suggest homologies. the hypothalamus of c. batrachus can be divided into the preoptic area, postoptic area, tuberal area and the laterally placed inferior lobes. application of cytoarchitectonic criteria permits the delineation of 9 distinct nuclear complexes in the preoptic area extending along the periventricular margi ...19911723419
pesticides induced changes in circulating thyroid hormones in the freshwater catfish clarias batrachus.1. effects of endosulfan, malathion and carbaryl on circulating t4, t3 and t3/t4 ratio in the freshwater catfish, c. batrachus have been studied during reproductively active phases, i.e. vitellogenic and post-vitellogenic phases of its annual reproductive cycle. 2. endosulfan provoked a significant increase in t4 and a decrease in t3 as well as the t3/t4 ratio. 3. malathion decreased t3 and t3/t4 ratio without altering the level of t4 in circulation. 4. carbaryl caused a decline in the level of ...19911677838
carbaryl-induced thyroid dysfunction in the freshwater catfish clarias batrachus.freshwater female catfish, clarias batrachus, were exposed to sublethal concentrations of carbaryl (12 mg/liter for 96 hr and 5 mg/liter for 16 days) during the prespawning and spawning phases of their annual reproductive cycle. the effects on the levels of thyroxine (t4) and triiodothyronine (t3), the t3/t4 ratio, and the extrathyroidal conversion of t4 to t3 were studied in serum, pharyngeal thyroid, and anterior and posterior kidney. carbaryl exposure for 96 hr suppressed t4 but elevated t3 a ...19911907904
effect of endosulfan on thyroid physiology in the freshwater catfish, clarias batrachus.effects of endosulfan on thyroid physiology have been studied in the female freshwater catfish. clarias batrachus during the pre-spawning and spawning phases of its annual reproductive cycle. effects of endosulfan varied with the length (96 h and 16 days) of exposure, reproductive status of the fish and organ. the 96-h endosulfan exposure significantly increased the level of thyroxine (t4) in serum and pharyngeal thyroid follicles concurrent with induction of peroxidase activity. however, triiod ...19912031252
outer membrane protein profiles of edwardsiella ictaluri from fish.outer membrane proteins (omp) prepared with sodium n-lauroyl sarcocinate (sls) from 33 edwardsiella ictaluri isolates from fish were examined by electrophoresis. twenty-eight isolates from channel catfish (ictalurus punctatus) had similar omp profiles. ten bands (71 kilodaltons [kd] to 19.5 kd) were identified in all isolates from channel catfish. one major 35-kd protein comprised most of the protein content of the outer membrane of isolates from channel catfish. differences existed among isolat ...19901689127
hepatic 5'-monodeiodinase activity in teleosts in vitro: a survey of thirty-three species.the in vitro hepatic 5'-monodeiodination of thyroxine (t4) to triiodothyronine (t3) in oreochromis mossambicus, channa striata, clarias batrachus, cyprinus carpio and oxyeleotris marmorata was found to be time, ph and temperature dependent, and related to the amount of substrate (t4) and homogenate introduced into the reaction vessel, in a manner which was consistent with menton-michaelis kinetics, and thus indicative of an enzyme-regulated process. dithiothreitol introduced into the reaction ve ...199024221892
purification and properties of liver arginase from teleostean fish clarias batrachus (l.).liver arginase of clarias batrachus has been purified to 56.3-fold employing ammonium sulphate fraction, deae-cellulose and cm-cellulose chromatography. bidirectional polyacrylamide gel electrophoresis shows the presence of two isoenzymes of arginase. the enzyme has a molecular weight of about 87,000 and km 15.38 mm for l-arginine, optimum ph 9.5 and temperature 37 degrees c. ornithine and leucine as competitive whereas valine and isoleucine act as non-competitive inhibitors with respect to l-ar ...19901705780
changes in hypothalamic catecholamine levels in relation to season, ovariectomy, and 17 beta-estradiol replacement in the catfish, clarias batrachus (l.).in female clarias batrachus, hypothalamic levels of noradrenaline (na) and dopamine (da) exhibited seasonal changes during different phases of the annual reproductive cycle. the na level was high during gonadal recrudescence (prespawning and spawning phases) and low during gonadal quiescence (postspawning and resting phases). a reverse trend was noticed in the da level. after 3 weeks of ovariectomy (ovx), the catecholamine (ca) levels were elevated significantly in the preparatory, prespawning, ...19902073997
changes in brain monoamine levels and monoamine oxidase activity in the catfish, clarias batrachus, during chronic treatments with mercurials. 19902383687
effect of quinalphos, organophosphorus insecticide, on testicular steroidogenesis in fish, clarias batrachus. 19902354263
enzymatic and ultrastructural studies in a freshwater catfish: impact of methyl parathion.exposure to a sublethal concentration of methyl parathion (mep) reduced the activity of cytoplasmic malate dehydrogenase, mitochondrial malate dehydrogenase, and lactate dehydrogenase by 30 to 49% in the liver and the skeletal muscle of the freshwater catfish. clarias batrachus, after 7 days. the activities then began to recover and reached the control levels on the 28th day of mep exposure. a complete recovery occurred on the 7th day when mep was withdrawn from the medium after an exposure for ...19902099789
evaluation of hematotoxic effects of two commonly used fertilizers, diammonium phosphate and urea, on fish clarias batrachus.the effects of two commonly used fertilizers, diammonium phosphate and urea, on hematological parameters (hemoglobin, red blood cell count, hematocrit, and total leucocyte count) of fresh water fish clarias batrachus were studied. the toxic effect of diammonium phosphate was more pronounced than that of urea. the toxic effect of diammonium phosphate resulted in a sudden fall of hematological parameters--hb, rbc count, hct--at higher concentrations, and at lower concentrations gradual decreases w ...19902159873
malate and lactate dehydrogenases of a freshwater catfish: impact of endosulfan.a sublethal concentration of technical grade endosulfan (end) inhibited 35 to 55% of the activities of cytoplasmic malate dehydrogenase (cmdh), mitochondrial malate dehydrogenase (mmdh), and lactate dehydrogenase (ldh) in the liver and the skeletal muscle of a freshwater catfish, clarias batrachus, after 7 days of exposure. the activity remained in the inhibited state up to 28 days. the withdrawal of end from the medium after 1 week of exposure gradually restored the activities to control levels ...19902331326
bioaccumulation of nickel and vanadium in tissues of the catfish clarias batrachus.bioaccumulation of nickel and vanadium in the tissues of the liver, kidney, gill, and intestine has been studied following 4 days and 30 days of exposure at sublethal concentrations of nickel and vanadium compounds in the catfish clarias batrachus. nickel and vanadium have been found to accumulate in all four tissues observed. high concentrations of nickel and vanadium have been found in the order kidney greater than gill greater than liver greater than intestine during the 4 days and 30 days tr ...19902329343
kinetic characterization and regulation of purified glutamine synthetase from brain of clarias batrachus.glutamine synthetase (gs) from brain of clarias batrachus is purified to about 42-fold and characterized at optimum ph and temperature with respect to its kinetic parameters. values for apparent michaelis constant of the enzyme for l-glutamine, hydroxylamine and adp are 50, 62.5 and 0.833 mm respectively. the very low apparent km for adp may be specially related to the expression of gs action under high energy bond and also be evidenced by the requirement of enzyme for a high ionic strength of t ...19901692700
the intrinsic organization of the nucleus preopticus in the catfish, clarias batrachus (linn.).the organization of magnocellular neurons of the nucleus preopticus (npo) of the catfisch, clarias batrachus is described with the help of nissl and aldehyde fuchsin stains and rapid golgi technique. the npo consists of a bilaterally located paraventricular group (pv) on either side of the preoptic recess and a supraoptic group (so) dorsal to the optic tract. the pv shows a vertical laminar arrangement--smaller cells located adjacent to the ependyma and larger ones farther away. on the basis of ...19901694195
changes in hypothalamic monoamine oxidase activity in relation to season, ovariectomy, and 17 beta-estradiol administration in intact and ovariectomized catfish, clarias batrachus (l.).cyclic changes in hypothalamic monoamine oxidase (mao) activity were noted during the annual ovarian cycle of clarias batrachus, with a high level in the preparatory phase and a low level in the spawning phase. administration of 17 beta-estradiol (e2) daily for 3 days induced both season- and dose-dependent responses in enzyme activity. in the preparatory phase, 0.05, 0.1, and 0.5 microgram/g doses of e2 enhanced enzyme activity in a dose-dependent manner, with significant changes being observed ...19892792729
toxic effects of mercurials on thyroid function of the catfish, clarias batrachus (l.).the toxic effects of mercurials on the thyroid activity of clarias batrachus were evaluated after exposure for 45, 90, and 180 days during gonadal recrudescence. histologically, the thyroid follicles were active with hypertrophied epithelium and reduced colloid content in 90- and 180-day mercuric chloride (hgcl2)- and 90-day methylmercuric chloride (ch3hgcl)-treated fish. in 180-day ch3hgcl and 90- and 180-day emisan 6 groups, the follicular epithelium appeared atrophic with a wavy and irregular ...19892501079
vanadium induced changes in glycogen content of clarias batrachus (linn) and channa punctatus (bloch).clarias batrachus (linn) and channa punctatus (bloch) were exposed to 5, 10 and 15 ppm of vanadium and investigated the effects on tissue glycogen at 3, 6 and 9 hrs. results indicated the variations in the level of glycogen were highest at 15 ppm after 9 hr exposure in liver than muscle, brain, kidney and heart of clarias batrachus as compared to channa punctatus. the variation recorded in tissue glycogen content was discussed in relation to respiratory distress, formation of mucus on the whole ...19892618741
influence of human urinary erythropoietin and l-thyroxine on blood morphology and energy reserves in two tropical species of fed and starved teleosts.erythropoietic responses of fed and starved species of teleosts, viz., clarias batrachus and heteropneustes fossilis, to human urinary erythropoietin and thyroxine have been examined. the effects of these hormones on energy reserves have also been evaluated. twenty-four c. batrachus were divided into two groups: half were fed regularly; the remaining fish were starved 20 days. on the 21st day each group was further divided into three subgroups of four each and received either saline, thyroxine ( ...19892583468
hypothalamic innervation of the pituitary in the catfish, clarias batrachus (l.): a retrograde horseradish peroxidase study.intrahypophysial administration of horseradish peroxidase (hrp) resulted in extensive labelling of the cells of nucleus preopticus and nucleus lateralis tuberis. besides, isolated retrogradely labelled neurons were observed in the nucleus preopticus periventricularis in the preoptic area, nucleus of the horizontal commissure, nucleus hypothalamicus ventralis in the rostral tuberal area, and nucleus arcuatus hypothalamicus in the caudal tuberal area. a few labelled cells were also observed in the ...19892616047
tissue glutamine synthetase associated with ammonia detoxication and nitrogen metabolism in clarias batrachus.the composition of reaction mixture of glutamine synthetase (gs) assay system was perfected and utilized to determine the activity of this enzyme spectrophotometrically in selected tissues of the freshwater teleostean fish, clarias batrachus. of these tissues, brain was found to contain comparatively a very high activity representing a rapid role of gs in ammonia detoxication and synthesis of essential neurotransmitter substance in this tissue. of other tissues, liver, kidney and gill were found ...19892476092
toxic effects of three mercurial compounds on survival, and histology of the kidney of the catfish clarias batrachus (l.).in clarias batrachus methylmercuric chloride (ch3hgcl) was 1.18 and 10.05 times more toxic than mercuric chloride (hgcl2) and emisan 6 (methoxyethyl mercury chloride), respectively, for 96 hr. a similar trend was observed at 24, 48, and 72 hr. exposure of the catfish to sublethal concentrations of these mercurials for 14 and 28 days caused progressive changes in the kidney. the diameter of the proximal convoluted tubules was increased, the epithelial cells were hypertrophied, and the lumen was r ...19883132362
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