The effect of malathion,diazinon, and various concentrations of zinc,copper, nickel,lead, iron,and mercury on fish

Acute and chronic toxicity tests for malathion, diazinon, copper (Cu), mercury (Hg), lead (Pb), zinc (Zn), nickel (Ni), and iron (Fe) were conducted. Mortalities ofBarilius vagra andCyprinus carpio (common carp) were variable but LC50-96 hr were similar for pesticides. AdultB. vagra seem to be more sensitive to malathion than juvenile carp. Both juvenile carp and adultB. vagra were extremely sensitive to diazinon. Long-term exposure to pesticides modified morphology and behavior. The LC50-96 values for Cu, Hg, and Pb were 0.3, 0.16, and 0.44, respectively, for smaller fish and 1.0, 0.77, and 1.33, respectively, for larger fish. Replicate LC50 values for Zn, Ni, and Fe were somewhat variable, and for these metals, the size of the fish seemed to affect response because LC50 values increased as fish size increased. Cooper, Pb, Zn, and Fe residues following exposure to sublethal concentrations of these metals for 15 d were significantly greater in whole juvenile common carp than in controls.     

Organophosphorus diazinon induced toxicity in the fish anguilla angvilla L.

1. Acute toxicity effects of diazinon on European eel (Anguilla anguilla) were examined using short-term exposures in static conditions.2. The lc₅₀ values found were: 0.16, 0.11, 0.09 and 0.08 mg/1 at 24, 48, 72 and 96 hr exposure, respectively.3. Eels were exposed to 0.056 mg/l of diazinon and the bioaccumulation and elimination of this insecticide in liver, muscle, gill and blood tissues were studied.4. BCF were 800 in liver, 1600 in muscle tissue and 2300 and 2730 in gill and blood tissue, respectively.5. The BCF₁ were 0.30 for liver, 0.60 for muscle and 0.84 for gill. Higher accumulation capacity of the gill was observed for the first hour of exposure.6. Diazinon elimination from the selected tissues was rapid, diazinon levels were not detected in any tissue after 24 hr in clean water.7. The excretion rate constants (K₂) of this insecticide were 0.023 hr⁻¹ for liver, 0.005 hr⁻¹ for gill and 0.019 ⁻¹ for muscle.8. Diazinon half-lives were calculated as 30.6, 32.2 and 38.3 hr for liver, muscle and gill, respectively.     

Accumulation and metabolism of 2,4,6-trichlorophenyl-4'-aminophenyl ether by carp

1. Accumulation of 2,4,6-trichlorophenyl-4'-aminophenyl ether (CNP-amino) in carp was investigated for 14 days. CNP-amino in carp could be divided into free CNP-amino [CNP-amino(I)] and bound CNP-amino [CNP-amino(II)]. 2. The bioconcentration factors (BCF) of CNP-amino(I + II) in carp were 90 +/- 38 (mean +/- SD, n = 3) for muscle, 402 for liver, 501 for kidney and 5368 for gallbladder after 14 days exposure. 3. 2,4,6-Trichlorophenyl-4'-acetamide phenyl ether (CNP-acetamide) was detected as metabolites of CNP-amino in muscle and viscera of carp.     

A generalized approach to detection of organophosphate resistance in mosquitoes

Insecticide bioassays and biochemical microtitre assays were compared for detection of resistance to the organophosphate insecticides malathion and fenitrothion, using inbred laboratory strains of malaria vectors Anopheles albimanus Wiedemann, An.arabiensis Patton and An.stephensi Liston. With susceptible mosquitoes, the LT100 values determined from bioassays corresponded closely with times taken to abolish the activity of acetylcholinesterase activity in biochemical assays: approximately 2 h for malathion and 3 h for fenitrothion. Resistant strains of all three anophelines showed longer survival correlated with prolonged acetylcholinesterase activity. An.albimanus strains with insensitive acetylcholinesterase survived bioassays with discriminating doses of 1 h exposure to 5% malathion or 1% fenitrothion and were judged as resistant. It is concluded that enzyme-specific microassays provide a reliable means of detecting resistant individuals, with practical advantages over bioassays which do not reveal the resistance mechanism and require large numbers of healthy mosquitoes.     

Accumulation of pollutants in fish

The amount of radioactivity which derived from 14C-labeled pollutants was determined in liver, kidney, intestine, blood, muscle and gills of carp, exposed for 6, 24 and 72 hr to high external concentrations of urea, methanol, atrazine and PCP. The results allowed one to calculate roughly the uptake rate for these compounds. It was low for urea (0.055 micrograms/g per hr), higher for methanol (0.12) and atrazine (0.16) and highest for PCP (1.5). The bioaccumulation factors (BFs) were determined for the different substances and organs. They correlated with the hydrophilic-lipophilic nature of the chemicals. The more lipophilic the substances the more accumulation occurred in the liver. PCP accumulated the most. BF was 300-400 in most tissues except muscle where it was quite low. The BF was 3-4 for atrazine in liver, kidney and intestine, but just 1 in blood, muscle and gills. There is some evidence that the BF for methanol equals 1 in liver, kidney, gills and intestine. It is less than 1 in blood and muscle. Urea was equally distributed in all organs and in the external medium.     

Effect of parathyroid hormone on renin secretion

The ability of parathyroid hormone (PTH) to increase renin secretion was investigated in pentobarbital-anesthetized dogs. An intravenous infusion of bovine PTH 1-34, at the dose of 0.028 microgram/kg-1 min-1 increased renin secretion by 149% (501 +/- 105 to 1249 +/- 309 ng hr-1 min-1); renin secretion returned to control values during the recovery period. In order to determine whether PTH acted directly on the kidney to increase renin secretion, PTH was infused into the right renal artery at doses of 0.0014 to 0.0028 microgram/kg-1 min-1 and renin secretion from the right kidney was compared to that from the left (control) kidney. Renin secretion from the right (PTH-infused) kidney was not greater than control values for that kidney or different from the renin secretory rate of the left (control) kidney. In contrast, the excretion rates of both phosphate and sodium from the right kidney were greater than control values and from the excretion rates of the left kidney. These data suggest that PTH, while acting directly on the kidney to increase phosphate and sodium excretion, does not elevate renin secretion by a direct renal action.     

Toxicity of organophosphorus insecticides to diazinon-reversely-selected,pesticide-pressure-relaxed and field-resistant strains of bulb miteRhizoglyphus robini (Acari: Acaridae)

Some field strains ofRhizoglyphus robini in Taiwan, developed high multi-resistance to organophosphorus insecticides including diazinon, dimethoate, fenitrothion, malathion, methyl parathion, omethoate, parathion and prothiophos. The organophosphorus resistance of bulb mites remained stable when the pesticide pressure was relaxed. Changes of the susceptibility to several organophosphorus insecticides for a strain after relaxation of selection pressure for 3 and 27 generations were compared. Since susceptible bulb mites could not be found in the field, a reverse selection for susceptibility to diazinon was designed and conducted. Although heterogeneity was observed in the progeny of the mixed populations, the susceptibility of these reversely-selected mites increased slowly. A stable and susceptible strain was obtained after 26 generations of selection.Contribution No. 1412 from Taiwan Agricultural Research Institute.     

Hypoxia and recovery perturb free radical processes and antioxidant potential in common carp (Cyprinus carpio) tissues

The effects of hypoxia exposure and subsequent normoxic recovery on the levels of lipid peroxides (LOOH), thiobarbituric acid reactive substances (TBARS), carbonylproteins, total glutathione levels, and the activities of six antioxidant enzymes were measured in brain, liver, kidney and skeletal muscle of the common carp Cyprinus carpio. Hypoxia exposure (25% of normal oxygen level) for 5h generally decreased the levels of oxidative damage products, but in liver TBARS content were elevated. Hypoxia stimulated increases in the activities of catalase (by 1.7-fold) and glutathione peroxidase (GPx) (by 1.3-fold) in brain supporting the idea that anticipatory preparation takes place in order to deal with the oxidative stress that will occur during reoxygenation. In liver, only GPx activity was reduced under hypoxia and reoxygenation while other enzymes were unaffected. Kidney showed decreased activity of GPx under aerobic recovery but superoxide dismutase (SOD) and catalase responded with sharp increases in activities. Skeletal muscle showed minor changes with a reduction in GPx activity under hypoxia exposure and an increase in SOD activity under recovery. Responses by antioxidant defenses in carp organs appear to include preparatory increases during hypoxia by some antioxidant enzymes in brain but a more direct response to oxidative insult during recovery appears to trigger enzyme responses in kidney and skeletal muscle.     

Human health risk assessment of organophosphorus pesticides in maize (Zea mays L.) from Yushu,Northeast China

In order to investigate organophosphorus pesticides (OPs) concentrations in maize and estimate the health risk to consumers, a total of 55 samples were collected from Yushu, one of the most important maize production areas. The concentrations of the eleven detected OPs in maize were analyzed by gas chromatography coupled with flame photometric detector (GC-FPD). The results showed that OPs concentrations of all maize were not higher than maximum residue limit (MRL), 67.3% of samples below MRL and only in 32.7% of samples was not found OPs. The mean concentrations obtained for the eleven OPs in μg kg^-1 were as follows: omethoate (0.8), quinalphos (0.8), phorate (0.7), dimethoate (0.7), parathion-methyl (0.6), isocarbophos (0.6), diazinon (0.5), fenitrothion (0.5), and malathion (0.5), with parathion (0.5) and fenthion (0.3). Phorate (16.4%), dimethoate (16.4%) and quinalphos (16.4%) had the highest frequency in the eleven OPs. 29.1% samples contained two or more kinds of OPs, while 38.2% samples detected one kind of OPs. The target hazard quotients (THQ) values were all less than one and the total acute hazard index (aHI) values for adults and children were 0.051 and 0.121, respectively indicating that consumer may not pose significant chronic and acute health risk through maize.     

Toxicity of cypermethrin in Labeo rohita fingerlings: biochemical,enzymatic and haematological consequences

The effect of exposure to sub-lethal concentrations of cypermethrin, a synthetic pyrethroid pesticide, on biochemical parameters of muscle, blood and enzyme activities in brain, liver and kidney of the Indian major carp, Labeo rohita was studied. The sub-lethal exposure studies were done for up to 45 days at 1/10 and 1/50 of 96 h LC(50) of cypermethrin. The 96 h LC(50) was found to be 0.139 ppm. RNA levels decreased while DNA levels were elevated. Acid phosphatase was unchanged while alkaline phosphatase was depleted. Brain acetylcholinesterase activity was decreased significantly (P<0.05) over a period of 45 days at both cypermethrin concentrations. Lactate dehydrogenase activity in brain and liver was elevated, but inhibited in kidney. Succinate dehydrogenase and ATPase activities were depleted in brain, kidney and liver. There was a decrease in serum protein level over control at both concentrations of the pyrethroid. Blood glucose level and total leucocytes were elevated compared with controls at either concentration from day 15 to day 45. Haemoglobin percentage and total erythrocytes decreased in both sub-lethal concentrations. Extracts of the herb Datura stramonium were effective in countering the toxicity of this pesticide. Our data suggest that sub-lethal exposure of cypermethrin alters the biochemical, haematological parameters and enzymes of organs tissue and exert stress on the fish. Plant extracts may be useful in counteracting some of these effects.     

Active ammonia excretion in the giant mudskipper, Periophthalmodon schlosseri (Pallas), during emersion

The main objective of this study was to determine whether active NH(4) (+) excretion occurred in the giant mudskipper, Periophthalmodon schlosseri, during emersion. Our results demonstrated that continual ammonia excretion in P. schlosseri during 24 hr of emersion resulted in high concentrations ( approximately 30 mmol l(-1)) of ammonia in fluid collected from the branchial surface. For fish injected intraperitoneally with 8 mumol g(-1) ammonium acetate (CH3COONH4) followed by 24 hr of emersion, the cumulative ammonia excreted was significantly greater than that of the control injected with sodium acetate. More importantly, the ammonia excretion rate at hour 2 in fish injected with CH3COONH4 followed by emersion was greater than that in fish immersed in water as reported elsewhere, with the greatest change in the ammonia excretion rate occurring at hour 2. Assuming that the rate of endogenous ammonia production remained unchanged, 33% of the exogenous ammonia was excreted through the head region, presumably through the gills, during the first 6 hr of emersion. Indeed, at hour 6, the ammonia concentration in the branchial fluid increased to an extraordinarily high concentration of >90 mmol l(-1). Therefore, our results confirm for the first time that P. schlosseri can effectively excrete a high load of ammonia on land, and corroborate the proposition that active NH(4) (+) excretion through its gills contributes in part to its high tolerance of aerial exposure. Only 4.6% of the exogenous ammonia was detoxified to urea. The glutamate contents in the muscle and liver also increased significantly, but the glutamine contents remained unchanged.     

Unusual physiology of scale-less carp,Gymnocypris przewalskii,in Lake Qinghai: a high altitude alkaline saline lake

The scale-less carp (Gymnocypris przewalskii) inhabits Lake Qinghai located on the Qinghai-Tibet plateau (elevation, 3200 m) in western China. The lake waters are alkaline (pH 9.4, titratable alkalinity=30 mmol l(-1)), Mg(2+)-rich (18.7 mmol l(-1)), Ca(2+)-poor (0.30 mmol l(-1)) and saline (9 per thousand ). These fish make annual spawning migrations into freshwater rivers. We investigated the physiology of nitrogen excretion and ionoregulation of fish from the lake and river. Fish from both waters were ammonotelic, although ammonia-N excretion rates were lower in lake fish (175 vs. 344 micromol kg(-1) h(-1), P<0.05) resulting in unusually high levels of ammonia in blood plasma (2.23 vs. 0.32 mmol l(-1)), bile, liver, muscle and brain. Exposure to 0.4 mmol l(-1) total ammonia in lake water ([NH(3)]=0.16 mmol l(-1)) killed fish within 8 h. River fish survived exposure to 1.0 mmol l(-1) total ammonia in river water at pH 8.0 ([NH(3)]=0.023 mmol l(-1)) for 24 h suggesting high ammonia tolerance in lake fish. High glutamate dehydrogenase and glutamine synthetase activities in tissues probably allow the fish to alleviate ammonia toxicity by amino acid accumulation. Neither lake nor river fish relied on urea excretion to remove excess N. Urea-N excretion rates were below 20 micromol kg(-1) h(-1) for both groups, and levels of urea in plasma and tissues were moderate. When exposed to elevated ammonia, urea-N excretion increased slightly (approximately 50 micromol kg(-1) h(-1)) and liver and muscle urea levels increased in the river fish. Plasma ion levels were within the range typical of cyprinids, but river fish had significantly higher plasma [Na(+)] and [Cl(-)] and lower [K(+)] than fish from the lake. During 48-h lake-to-river water transfer, plasma Na(+) and Cl(-) levels rose significantly. Significantly higher Na(+)/K(+)-ATPase activity in the gills of river fish may be related to the higher plasma ion levels. Plasma [Mg(2+)] and [Ca(2+)] were tightly regulated despite the great differences in the lake and river water levels.     

Effect of glucamylase on tissue glycogen and tissue glucamylase in the rat

1. A fungal glucamylase (alpha-1,4-glucan glucohydrolase, EC 3.2.1.3) from Aspergillus niger depresses liver glycogen stores after intraperitoneal injection into the rat. The injected enzyme rapidly disappears (within about 8hr.) from the serum; less than 1% is excreted in the urine, but it is rapidly taken up in the liver, spleen, kidney, cardiac and skeletal muscle. Elevated glucamylase concentrations could be demonstrated in liver and spleen tissues for 1-4 days after injection, but in kidney, cardiac and skeletal muscle elevated glucamylase concentrations could be shown only for periods of less than 24hr. after injection of the enzyme.     

Cellular effects of adrenosterone feeding to juvenile carp, Cyprinus carpio L., effect on liver, kidney, brain and muscle protein and nucleic acids

Different groups of juvenile common carp (3–4 g) were fed diets supplemented with adrenosterone at doses of 1.0, 2.5 and 10.0 mg kg^-1 for 60 days and the effect on food conversion efficiency and cellular growth responses of liver, kidney, brain and muscle were investigated. At the end of the hormone feeding phase an increase of 40–75% was observed in food conversion efficiency. No change in hepato-somatic and viscero-somatic index was observed, but brain and kidney weights in relation to body weight was decreased compared with the controls. Variable changes in protein, RNA/DNA, protein/RNA and protein/DNA were seen in liver, kidney, brain and muscle. Feeding of the steroid for 60 days increased the water content of the muscle but ash contents of the muscle were decreased. No change in the total muscle lipids and total nitrogen content were observed. After the removal of the drug from the feed, some of the changes reported were ameliorated.     

Distribution and peroxidative oxidation of 2-t-butyl-4-methoxyphenol in rat tissues after a single intraperitoneal dose

The distribution of 2-t-butyl-4-methoxyphenol (BHA) and its conversion to 2,2'-dihydroxy-3,3'-di-t-butyl-5,5'-dimethoxydiphenyl (di-BHA) in rat tissues at different times (1-96 hr) following the intraperitoneal administration of a single dose of BHA (32 mg kg-1 body weight) were monitored by gas chromatography-mass spectrometry (GC/MS) analysis of both compounds. High BHA levels were found in the intestine and liver persisting up to 24 hours (5.5-20.7 and 1.8-3.3 micrograms g-1 wet weight, respectively). In these tissues, values of the area under the experimental concentration curve (AUC0-24) were 285 and 49 times higher, respectively, than those observed in plasma (945 ng mL-1 hr), AUC0-24 values in kidney, spleen, erythrocytes, and brain were 2-7 times higher, whereas values below those found in plasma were observed in lung and muscle. The metabolite di-BHA could be detected in the intestine, kidney, and spleen, amounting to 5-8% of BHA. These findings indicate that rat intestine is capable of transforming in vivo BHA into di-BHA even when the former compound is administered intraperitoneally and that this capacity is shared by the kidney and spleen.     

The effect of intraperitoneally administered gold thioglucose on growth, food consumption and accumulation of gold in various organs of the chicken (Gallus domesticus)

1. Gold thioglucose (GTG) was intraperitoneally injected into 10-day-old male and female chickens in a dose of 0, 0.2, 0.4 or 0.8 mg per gram of body wt. 2. Mortality of the GTG-injected chickens was 100% and 25% for doses of 0.8 and 0.4 mg/gBW respectively, in both sexes and 25% for a dose of 0.2 mg in females, which were all found within 14.5 hr after the GTG treatment. 3. Body weight gain, food consumption and food efficiency of surviving chickens for 23 days after the GTG injection were not affected by GTG in spite of dose level. 4. Gold detected in blood, heart, liver, gallbladder, spleen, proventriculus, gizzard, duodenum, kidney, pectoral muscle, small intestine, lung and brain of the dead chickens accumulated most highly in heart and followed by spleen, but in the surviving chicken a little gold was only found in liver, spleen and kidney of some GTG-treated chickens.     

Effects of insecticides on the foraging behaviour and survival of Cotesia vestalis,a larval parasitoid of the diamondback moth,Plutella xylostella

The effects of the insecticides etofenprox, malathion, diazinon, methomyl, alanycarb, clothianidin and emamectin benzoate on the foraging behaviour and survival of Cotesia vestalis (Hymenoptera: Braconidae), a larval parasitoid of the diamondback moth Plutella xylostella (Lepidoptera: Plutellidae) were investigated in the laboratory. The period required for C. vestalis females to reach P. xylostella‐infested Komatsuna (Brassica rapa) plants treated with etofenprox, methomyl or malathion was significantly longer than that to infested plants treated with emamectin benzoate or clothianidin; and the period to reach alanycarb or diazinon‐treated plants was intermediate between them. The period to reach emamectin benzoate‐ or clothianidin‐treated plants was not significantly different from that to distilled water‐sprayed plants, suggesting that etofenprox, methomyl and malathion have strong inhibitory effects on the flight response, whereas the inhibitory effects of alanycarb and diazinon are relatively weak. By contrast, emamectin benzoate and clothianidin showed no inhibitory effect. The time of residency on the clothianidin‐treated plants was significantly longer than that on other insecticide‐treated plants (etofenprox, methomyl, alanycarb, malathion or diazinon), with the time of residency on emamectin benzoate‐treated plants being intermediate between them. These results suggest that etofenprox, methomyl, alanycarb, malathion, and diazinon have a strong inhibitory effect on host‐searching behaviour, while emamectin benzoate and clothianidin have a relatively weak effect. Furthermore, the mortality of wasps after foraging on the clothianidin‐treated plants was significantly higher than after foraging on other insecticide‐treated plants (etofenprox, methomyl or malathion), with subsequent mortality on alanycarb‐, diazinon‐ and emamectin benzoate‐treated plants being intermediate between them. Our results suggest that subsequent mortality increases with decreased inhibitory effect on the foraging behaviour of C. vestalis.     

Toxic Effects of Paraquat on Cytokine Expression in Common Carp,Cyprinus carpio L.

In this study, the acute toxicity of paraquat (PQ) in common carp was determined. Then, the contents and mRNA levels of the cytokines interleukin‐1β (IL‐1β), interferon‐γ (IFN‐γ), and tumor necrosis factor‐α (TNF‐α) were evaluated following subacute exposure to PQ. The results show that the LC₅₀ of PQ for common carp at 72 and 96 h was 15.962 and 15.106 mg/L, respectively. Moreover, after 7 days of subacute PQ exposure, the IL‐1β content in the fish liver and kidney increased, although it decreased in spleen. However, changes in the IFN‐γ content showed an irregular trend. The TNF‐α content increased in the liver and spleen but decreased in the kidney. Additionally, PQ exposure also induced alterations in the mRNA levels of IL‐1β, IFN‐γ, and TNF‐α. These results suggest that PQ exposure may result in suppression or excessive activation of the immune system in treated fish and lead to immune dysfunction and reduced immunity.     

The effects of temperature, salinity and a simulated tidal cycle on the toxicity of fenitrothion to Callinectes sapidus

The 96 hr LC50 for Callinectes sapidus exposed to fenitrothion at 22 degrees C and a salinity of 34 ppt (parts per thousand) was estimated to be 8.6 micrograms/l with a 95% confidence interval of 7.4-9.9 micrograms/l. Acute toxicity was shown to increase with increasing temperature as well as increasing salinity. Exposure of Callinectes to a simulated tidal cycle of 17 ppt salinity change at 6 hr intervals increased the acute toxicity of fenitrothion to Callinectes. The autotomization response in Callinectes was shown to be affected at subacute exposure levels as low as 0.1 microgram/l.