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1.
Exposure of a freshwater cyprinid (Puntius conchonius) to 2.142 and 4.784 ppm of carbaryl and dimethoate, respectively, for 24 hr, seriously affected carbohydrate and cholesterol metabolism. Significant hyperglycemia and glycogenolysis in liver, brain, and heart were manifested in the treated fish. Hypercholesterolemia and rise in liver cholesterol also occurred. Long-term exposure, 15–30 days, to chronically sublethal concentrations, 0.194 and 0.306 ppm carbaryl and 0.434 and 0.683 ppm dimethoate, elicited hypoglycemia and depletion of liver glycogen, together with enhanced glycogenesis in the heart. The glycogen level in brain fell in response to carbaryl exposure in contrast to a significant elevation caused by dimethoate. Reduction in blood and liver cholesterol at 15 days was followed by an increase at 30 days.  相似文献   

2.
The present study was aimed to investigate the effects of purified neem extract azadirachtin on the blood electrolytes of Heteropneustes fossilis for short- and long-term. In short-term exposure the fish were subjected to 0.8 (i.e. 80%) of 96 h LC50 value of azadirachtin (41.89 mg L−1) for 96 h. In long-term exposure the experiment was performed for 28 days by using 0.2 (i.e. 20%) of 96 h LC50 value of azadirachtin (10.47 mg L−1). Fish were sacrificed (anaesthesized with MS 222) from control and experimental (azadirachtin) groups after 24, 48, 72, and 96 h in short-term exposure and after 7, 14, 21, and 28 days in long-term experiment. Blood samples were analyzed for calcium and inorganic phosphate levels. Acute exposure of azadirachtin caused a progressive decrease in the serum calcium levels after 48 h in fish H. fossilis which persists till the close of the experiment (96 h). The serum inorganic phosphate levels remained unaffected till 72 h in the azadirachtin exposed fish. After 96 h the levels exhibit a decrease. Chronic azadirachtin treatment caused a decrease in serum calcium levels at day 14. This decrease continued till the end of the experiment. The serum phosphate level of the azadirachtin treated fish decreased on day 14 and 21. However, on day 28 the levels were close to the normal values.  相似文献   

3.
Sublethal effect of monocrotophos (pesticide) and ammonium chloride (fertilizer) was studied in the freshwater fish Oreochromis mossambicus, with reference to carbohydrate metabolism for a period of 96 h. The glycogen content was analysed in liver and muscle, while the lactate and pyruvate were assessed in blood along with liver and muscle. The results revealed that the glycogen content was found to be decreasing. In contrast increase in the tissues lactate and pyruvate level was found in the fishes exposed to pesticide and fertilizer individually and in combinations. The combined effects of these chemicals were more toxic to carbohydrate metabolism than the effect produced by the individual chemicals. The results were tested to search for statistical significance. The calculated lactate and pyruvate ratio (L/P) indicated that the fishes were under chemical stress.  相似文献   

4.
The effects of an acute lethal (0.59 mg/liter) and a sublethal (0.075 mg/liter) concentration of lindane on the levels of glycogen (liver and muscle), glucose (blood), and lactic acid (liver, muscle, and blood) of a freshwater fish, Anabas testudineus (Bloch) were determined. A marked decrease in the liver glycogen and significant increase in blood glucose and muscle glycogen at 1 hr of exposure to 0.075 mg/liter lindane was noted. These results indicate extensive utilization of energy stores in the liver and simultaneous buildup of fuel reserves in the muscle. After 3 hr of exposure, glycogenesis possibly becomes operative in liver through the Cori cycle. The activity of the cycle was observed in the fish in all the subsequent periods of exposure studied. At 120 hr, the decreases observed in muscle and liver glycogen indicate near exhaustion of glycogen stores. Though changes in glycogen content of both muscle and liver were similar in 0.59 mg/liter lindane, they have less adaptive value since mortality of fish was significantly high at all three peroids studied.  相似文献   

5.
The long-term effect of endosulfan on the carbohydrate metabolites of the fish Anabas scandens was studied. Exposure of fish to a sublethal concentration of 6 ppb, for a period of 21 days resulted in marked changes in total carbohydrate, glycogen, lactic acid, and pyruvic acid content of the tissues. Lactate levels were found to be elevated, whereas pyruvate and glycogen content of the tissues declined. The results indicate that exposure of fish to endosulfan leads to metabolic adaptations to suit the functional need of the animal.  相似文献   

6.
Alterations in the levels of hemoglobin, total plasma proteins, glucose, and lactic acid in the blood; glycogen and lactic acid content of liver and white skeletal muscle; and the activities of lactate dehydrogenase, pyruvate dehydrogenase, and succinate dehydrogenase in liver, kidney, intestine, brain, gills, and muscles were examined in the fresh-water snake-head fish, Channa punctatus, after exposure to a sublethal concentration (25 μg/liter) of quinalphos for 60 and 120 days. Hemoglobin, plasma protein, glucose, and lactic acid decreased in pesticide-exposed fish. The glycogen content of the liver and muscles increased but lactic acid decreased. Lactate dehydrogenase activity decreased in all six tissues. Pyruvate dehydrogenase activity of liver, kidney, gill, and muscle decreased, but the enzyme activity was elevated in intestine and brain. In intestine, succinate dehydrogenase activity was elevated, and in the remaining five tissues the enzyme activity was significantly reduced. The present study showed that formation of glycogen and its breakdown was impaired in the liver, and aerobic oxidation of nutrients was adversely affected in quinalphos-exposed fish.  相似文献   

7.
The sublethal effect of a synthetic pyrethroid, cypermethrin on total protein, amino acids, ammonia, glycogen, and enzymes like aminotransaminases (AIAT, AAT), glutamate dehydrogenase, and glycogen phosphorylases (a and ab) was studied in physiological important tissues viz; liver and gill tissues of freshwater teleost air breathing fish, Clarias batrachus. The study was conducted during exposure of 1/3 (33%) of LC50 concentration and followed by cessation of exposure. Thirty-six fish were exposed to 0.07 mg/L cypermethrin for 10 days. After 10 days, 18 fish were released to freshwater and kept in the same for 10 days (recovery group). Thirty-six fish were kept in freshwater as control batch. Protein content in liver tissues decreased at the end of 1st and 5th day followed by slight increase at the end of 10th day. Gill tissue showed statistical significant decrease (P < 0.001) in protein content during exposure period of 10 days. Recovery in protein content was observed to a large extent in both the tissues. Total free amino acids were increased in liver and gill tissues throughout the treatment period, recovery response was seen after cessation of exposure. Ammonia level was decrease in both the tissues throughout the exposure period except in liver tissue at the end of 1st day of exposure. Recovery response was exhibited by both the tissues. A decreased in glycogen content of liver tissue was observed during exposure period, gill tissue also showed decrease in glycogen at the end of 1st and 5th day followed by increase at the end of 10th day of exposure period. When the fish were transferred to freshwater, recovery in glycogen content was noted. The activity level of alanine, aspartate aminotransaminase, glutamate dehydrogenase, and phosphorylases (a, ab) was increased in both the tissues, followed by recovery response after released of fish into freshwater. The present study showed that cypermethrin caused alterations in certain biochemical mechanisms of C. batrachus. This fish indicated recovery response when transferred to cypermethrin free water.  相似文献   

8.
The toxicity of topically applied DDT to adult female anautogenous mosquitoes (Culex pipiens L.) showed dramatic variations in blood-fed insects. It decreased very rapidly about twofold to a minimum at 24 hr after a blood meal, then increased within 72 hr back to values typical of non-blood fed insects. A comparison of the metabolism of [14C]DDT in vivo revealed an increase in DDT dehydrochlorination to DDE at 72 hr after a blood meal, but this increase was not responsible for the variations in DDT toxicity at 24 hr. Changes in penetration rates were not observed and changes in the distribution of DDT could likewise not be related to the short period of decreased toxicity of DDT. Fenvalerate and trans-permethrin, two pyrethroid insecticides which are believed to have a mode of action similar to that of DDT, were also significantly less toxic 24 hr after a blood meal. By contrast, the cyclodiene insecticide aldrin and the carbamate insecticide propoxur were not less toxic 24 hr after a blood meal. The results suggest that after a blood meal an unidentified and transient change in C. pipiens specifically decreases DDT/pyrethroid toxicity. A hypothesis concerning this transient change is advanced. The results illustrate the difficulties in explaining physiological changes in insecticide toxicity.  相似文献   

9.
A rat hepatocyte suspension effectively epoxidized aldrin to dieldrin with a Vmax of 7.19 mol/mol P-450/min and a Km of 9.27 μM. Viability and metabolic activity were stable for 6 hr after isolation when cells were maintained at room temperature (20°C) with the gentle introduction of O2CO2 onto the surface of the suspension. The cytochrome P-450 content of the suspension was 303 pmol/106 cells. Primary maintenance culture of the cells also epoxidized aldrin. During culture for 3 days, metabolic activity decreased slowly day by day. Metabolic activity of microsomal fraction from rat liver was also examined. Microsomes epoxidized aldrin with a Vmax of 5.11 mol/mol P-450/min and a Km of 1.64 μM. Significant loss of some subspecies of cytochrome P-450 during fractionation of liver homogenate was indicated.  相似文献   

10.
The effects of piperonyl butoxide on metabolism of 14C-labeled methoxychlor, aldrin, and trifluralin were investigated in green sunfish, Lepomis cyanellus. Piperonyl butoxide inhibited epoxidation of aldrin to dieldrin, O-dealkylation of methoxychlor, and N-dealkylation of trifluralin, resulting in higher levels of total radioactivity in animals exposed to the combination compared to those exposed to pesticide alone. Where piperonyl butoxide was present a greater proportion of the total radioactivity in the fish extract occurred as parent compound compared to metabolites than in fish exposed to pesticide alone. After 16 days of exposure piperonyl butoxide increased the proportion of parent compound eight times for methoxychlor, 17 times for aldrin, and 15 times for trifluralin.  相似文献   

11.
Five experimental diets with various combinations of probiotics, namely T1 & T6 (basal feed (BF) without probiotics), T2 & T7 (BF + Bacillus subtilis + Lactococcus lactis), T3 & T8 (BF + L. lactis + Saccharomyces cerevisiae), T4 & T9 (BF + B. subtilis + S. cerevisiae) and T5 & T10 (BF + B. subtilis + L. lactis + S. cerevisiae) were fed to Labeo rohita fingerlings for 30 days. Treatment groups T1, T2, T3, T4 and T5 were exposed to Fenvalerate, at a concentration of 1.79 μg L−1. The SOD and CAT activity was significantly affected (P < 0.01) in fenvalerate treated groups. However, the supplementation of the three-probiotic mixture at equal concentration showed markedly reduced activity. Similarly, RBC, Hb, NBT, total protein and albumin values were reduced significantly (P < 0.01) in the fenvalerate exposed fish as compared to the probiotic supplemented fish. Fenvalerate exposure also showed increased serum ALP, ACP and Bilirubin values (P < 0.01) in comparison to the non-exposed fish. Histological observations of the gills, kidney and liver showed tissue degeneration after fenvalerate exposure, which however showed marked recovery on the three-probiotic mixture supplementation. Therefore, these results indicate that a mixture of multi-species probiotic supplementation in equal concentration acts beneficially in mitigating the stressful effects of fenvalerate.  相似文献   

12.
Experiments were conducted with the freshwater fish Macrognathus aculeatum to study the toxicity and metabolism of endosulfan and the effect of the pesticide on the oxygen consumption and total nitrogen excretion. The 96-hr LC50 value was 3.5 ± 0.2 ppb. In brain, gills, gut, liver, and kidney, endosulfan was metabolized to endosulfan sulfate, but this appears to be only an intermediary step as the nontoxic endosulfan ether was found only in the liver and kidney, the principal organs of elimination of toxicants in fish. The pesticide, both at sublethal and lethal concentrations, decreased oxygen consumption and total nitrogen excretion.  相似文献   

13.
Carbohydrate metabolism was studied in the hepatopancreas, mantle, intestine and foot of the snail Lymnaea acuminata, exposed to 40% and 80% of the LC50 dose of phorate (12 and 24 mg litre?1, respectively) for 24 and 48 h. Following treatment with the pesticide, the rate of oxygen consumption and the glycogen contents were reduced, while the levels of lactic acid and reducing sugars were enhanced. Withdrawal of the pesticide for 7 days after exposure of the snails to 12 mg of phorate litre?1 for 48 h did not reverse these changes.  相似文献   

14.
Penetration and metabolism of [14C]vernolate in soybean [Glycine max (L.) Merr. var Ransom] pods and seeds were measured 0, 1, 4, 24, 48, or 72 hr after treatment which occurred at 40 days after flowering. Total 14C recovery decreased ca. 50% within 4 hr and the loss of 14C was considered to be a measure of volatility. Total nonpolar extractants decreased in a logarithmic pattern which approached 10% of total 14C recovered within 24–48 hr. Total polar extractants increased in a logarithmic pattern to a maximum of 90% of total 14C recovered within 24 hr. Seed nonpolar extractants never exceeded 2% of the total 14C recovered while pod nonpolar extractants consisted of vernolate plus an unidentified component that did not thin-layer chromatograph (TLC) as the sulfone or sulfoxide. Pod polar extractants increased with time to ca. 75% of the total 14C recovered (24–48 hr) and decreased to ca. 58% at 72 hr after treatment. Seed polar extractants averaged ca. 10% of total 14C recovered for the first 48 hr after treatment and then increased to 30% of total 14C recovered. Thus, [14C]vernolate per se concentration decreased to <1% of applied material within 72 hr through volatilization and degradation of nonpolar extractants to polar products. Polar metabolites showed two major patterns of vernolate detoxification. One detoxification system produced 14C-metabolites whose Rf's were equivalent to that reported in corn (Zea mays L.) [J. P. Hubbell and J. E. Casida, [J. Agric. Food Chem. 25, 404 (1977)] and accounted for <30% of the pod polar extractants. A second detoxification system was most prevalent in soybean pod and seed tissues and resulted in very rapid modification of vernolate with an unidentified product that was 85% of the extracted 14C within 4 hr after treatment and which decreased in concentration with time. Therefore, unexplained vernolate detoxification system(s) exist in soybean pod and seed.  相似文献   

15.
毒死蜱对稀有鮈鲫不同生命阶段的毒性效应   总被引：3，自引：1，他引：2  
为探明毒死蜱对鱼类不同生命阶段的毒性效应,以稀有鮈鲫Gobiocypris rarus为测试生物,评价了毒死蜱对其的急性毒性及对胚胎生长发育的毒性效应。结果表明:毒死蜱对稀有鮈鲫胚胎、仔鱼、幼鱼和成鱼的96 h-LC50值分别为7.59(5.14~9.86)、0.393(0.326~0.447)、0.047 8(0.038 2~0.054 9)和0.027 2(0.021 9~0.041 9)mg/L,毒死蜱对稀有鮈鲫4个生命阶段的毒性大小依次为成鱼幼鱼仔鱼胚胎;稀有鮈鲫暴露于毒死蜱后最明显的中毒症状是脊柱畸形;此外,质量浓度为6.13~35.8 mg/L的毒死蜱在48 h时可明显促进稀有鮈鲫胚胎的孵化。  相似文献   

16.
Tests of acute toxicity were performed on the most common species of aquarium fish, Poecilia reticulata. Guppies (P. reticulata) were exposed to progressive concentrations of methyl parathion (MP) and chlorpyrifos (CPF); a semi-static method according to guidelines of OECD was used. Tests of acute toxicity were conducted using 10 fish for each separate concentration and for the control group. The results were subjected to probit analysis to determine the 96 h LC50 values. The 96 h LC50 values of MP and CPF to P. reticulata were 8.48 ppm/L (5.98–10.89) and 0.176 ppm/L (0.313–0.224) respectively. In addition, behavioral changes at each concentration were observed for the individual fish. Fish were exposed for 96 h to different sublethal concentrations of MP and CPF (¼ LC50, 1/8 LC50 and 1/10 LC50) and their oxidative stress-induction potential was estimated in brain, liver and gills of fish. MDA content is induced in all tissues but maximum rise was observed in gills (161% and 153% for MP and CPF respectively). With regard to antioxidant defense system (ADS), GSH level decreased in the brain, liver and gills of tissues of MP treated fishes (22%, 6% and 13% respectively) and showed increase in brain and gills CPF treated (23% and 21% respectively). CAT, GST, GR and SOD levels fluctuated in all treatment groups relative to the control. Brain AChE showed dose-dependent inhibition in fish exposed to the higher concentrations reached 45% and 66% for MP and CPF respectively. Collective findings demonstrated that pesticide exposure of fish induced an increase in MDA and fluctuated ADS along with inhibited AChE. These findings may be used as valuable biomarkers for evaluation of water pollution.  相似文献   

17.
The main objective of this study is to investigate the 24 h kinetic effect of acute administration of malathion, an organophosphorus insecticide, on glucose homeostasis in adult rats. A single dose of malathion (400 mg/kg, 1/5 of LD50) was administered orally to rats, blood glucose was measured, liver and pancreas were removed to determine the level of hepatic glycogen, the activity of pancreatic acetylcholinesterase and butyrylcholinesterase, as well as the level of TBARs. Blood glucose increased in rats treated with a single dose of malathion. This effect was observed in the first hours of treatment, reached a 2.2 fold peak after 2 h, and then decreased after 4 h, followed by a decrease in the level of hepatic glycogen. The storage of glycogen starts from 6 to 12 h of administration. A decrease in cholinesterase activities was noted. The level of TBARs increased considerably in liver and pancreas. Results of this study can be explain by a stimulation of glycogenolysis and gluconeogenesis by liver, with a temporarily loss of endocrine functions of pancreas leading to hyperglycemia.  相似文献   

18.
Adaptive changes in the levels of carbohydrate metabolites, glucose, glycogen and lactic acid, were studied in a freshwater edible fish, Sarotherodon mossambicus exposed to a carbamate fungicide, ziram. Based on the results obtained, it was concluded that the fish showed (i) adaptive utilization of stored glycogen, particularly in liver tissue; (ii) adaptive accumulation of glycogen in muscle and heart tissues, probably by glyconeogenesis and (iii) adaptive mechanism of operation of ‘diving syndrome’, to meet the stress of the pollutant under sub-lethal exposure. © 1998 SCI.  相似文献   

19.
Soybean [Glycine max (L.) Merr., cv. Swift] plants at the second trifoliate leaf stage and rice (Oryza sativa L. cv. Starbonnet) plants 25 cm tall were treated with 0, 0.56, and 2.24 kg/ha of fentin hydroxide (triphenyltin hydroxide) to determine the effect of this fungicide on photosynthesis, respiration, and leaf ultrastructure. Photosynthesis and respiration were measured with an infrared CO2 analyzer in an open flow system prior to fentin hydroxide application and at 4, 24, 48, and 96 hr after treatment with fentin hydroxide. No significant detrimental effects on photosynthesis or respiration were evident in either soybean or rice through 96 hr after treatment. Tissue samples from soybean and rice plants, 9 days after fentin hydroxide application, examined for ultrastructure changes with the transmission electron microscope showed no effect due to the fungicide treatment.  相似文献   

20.
在试验室条件下,研究了芜菁夜蛾线虫北京品系与亚洲玉米螟幼虫接触时间,对玉米螟死亡率和死亡速度的影响。结果表明,线虫与玉米螟接触时间在0.5、1、2小时内,玉米螟死亡率随时间的延长而增加,分别为35.3、50.7和61％。4小时以上各处理玉米螟死亡率均达92％以上,差异不明显。线虫与玉米螟接触0.5、8和12小时,其寄主体内进入的线虫数分别为1.2、7.9和23.8～28.3条/虫。玉米螟幼虫的死亡速度也随进人体内线虫数增多而加快,进入一条线虫的寄主在48～96小时内死亡,2～5条线虫的72小时内死亡,6～30条的48小时死亡,31条以上的24小时内死亡。  相似文献   

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