Effects of phosphorothionate on the reproductive system of male rats

Acute and Sub-acute toxic effects of a new pesticide phosphorothionate coded as RPR-V on testis of albino rat were studied. For the acute study, rats received a single dose of 30 mg/kg of RPR-V and sacrificed after 24 hours. For the Subacute study, 1.42 mg/kg/day was administered orally to rats for 10 days and 21 days. Acute exposure of rats to RPR-V brought no change either in the Gonadosomatic Index (GSI) or in the structure of testis or in the serum levels of Testosterone. Similarly, no significant change was observed in the Glutathione S-transferase (GST) activity. But, in testis there was significant increased in the reduced Glutathione (GSH) and Acid Phosphatase (AcP), whereas Alkaline Phosphatase (AkP) levels decreased significantly at 24hr post treatment. On 7th day (withdrawal period) after the cessation of the treatment the GSH, AcP, and AkP levels reached to near control. The sub-acute study revealed a significant post treatment. Due to RPR-V treatment the testis AcP levels increased significantly at 21st day of medication but AkP levels decreased both at 10th and 21st day of post treatment. Histopathological studies showed that after 10th day testis showed considerable loss of spermatozoids and at 21st day complete derangement of cellular organization was observed. Testosterone levels decreased significantly after 10th day and remained significantly low at 21st day. However, withdrawal studies showed a recovery in testis of rat treated with RPR-V. GST, GSH, GSI, AcP and AkP values were recovered, testosterone levels were also recovered but recovery in testis structure remained at a low profile.     

The effects of ethylene chlorohydrin on fatty acid synthesis 1 2 3

Abstract

Male chicks weighing 700 to 900 g. received an acute or eight doses IG of 60 or 40 mg/kg ethylene chlorohydrin (ECH) respectively and were sacrificed eighteen hours after the last dose. Mitochondrial elongation of fatty acids was decreased significantly while fatty acid synthetase activity was not significantly affected by ECH treatment. Cytochrome c oxidase activity in fresh whole liver homogenate was significantly higher in chicks subjected to acute exposure with ECH when compared to the controls. Upon freezing and thawing of homogenates, cytochrome c oxidase activity increased significantly in the control group but was unchanged in the ECH group which suggests that the mitochondrial membrane integrity is compromised by the ECH treatment. Serum and liver triglyceride levels were significantly elevated in both the single and multiple ECH dose groups. Liver to body weight ratios were significantly higher in both treatment groups when compared to their controls. Histological examination of the liver of ECH‐treated chicks showed cytoplasmic clearing of the cells but no vacuolization or centri‐lobular necrosis. Serum isocitrate dehydrogenase levels were significantly higher in the multiple treatment ECH group than in the control group.     

Mixture effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and polychlorinated biphenyl congeners in rats

Concern of the toxic effects and bioaccumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated biphenyls in the environment continues to be a focus of research in persistent organochlorine contaminants. Groups of five adult female S.D. rats were administered by gavage 0, 2.5, 25, 250 or 1000 ng TCDD/kg body weight/day or TCDD in combination with a mixture of PCB congeners (PCBs) at 2 or 20 microg/kg b.w./day for a period of 28 days. Growth suppression, increased absolute and relative liver weights, and decreased thymic weight were observed in either the 1000 ng TCDD group alone, or the groups receiving a mixture of 1000 ng TCDD + 2 microg PCBs. The TCDD induced increases in liver and thymic weights were not altered by co-administration with PCBs, however, growth suppression appeared to be more pronounced in the group receiving 1000 ng TCDD + 2 microg PCBs than with TCDD alone. Treatment with TCDD at 250 ng and 1000 ng/kg resulted in a significant increase in hepatic microsomal methoxy resorufin-O-demethylase and ethoxy resorufin-O-deethylase activities which were antagonized by co-administration with PCBs. Similarly, effects of 250 ng TCDD on serum cholesterol and liver UDP glucuronosyl transferase activity and ascorbic acid were significantly reduced by co-administration with 20 microg PCBs. Other biochemical effects elicited by treatment with 1000 ng TCDD, but not affected by co-administration with PCBs include the following: increased serum albumin, decreased liver vitamin A, and increased kidney vitamin A and liver microsomal glutathione-S-transferase activity. While decreased hemoglobin, platelet, packed cell volume and red cell indices were observed in TCDD treated rats, no interactive effects were seen. The above results indicate that the mixture effects of PCBs and TCDD may be additive or antagonistic depending on the dose level and endpoints measured. For the purpose of predicting mixture effects, knowledge of mechanisms of action and toxicokinetics is required.     

TCDD (2,3,7,8-tetrachlorodibenzo-P-dioxin) causes reduction in glucose uptake through glucose transporters on the plasma membrane of the guinea pig adipocyte.

A single dose of 2,3,7,8-TCDD (1 micrograms/kg, i.p. injection) resulted in a significant decrease in cellular 3-O-methyl-[3H]-glucose uptake by guinea pig adipose tissue and pancreas after 24 hours. An in situ tissue culture study in which pieces of adipose tissue were incubated with 10(-8)M TCDD showed a time-dependent decrease in glucose uptake. Reconstitution of adipocyte plasma membrane from tested or control animals into artificial liposomes also resulted in this difference in glucose uptake. Binding of [3H]-cytochalasin B, a specific inhibitor of glucose transporter proteins, was significantly lower in acetone-ether powder preparations of TCDD-treated adipose tissue than from controls, suggesting that the total titer of these proteins is decreased by TCDD. Finally, the relevance of these results to glucose or lipid metabolism was tested. Lipoprotein lipase (LPL) activity of guinea pig adipose tissue was decreased after 8 hours of in situ incubation with TCDD indicating that glucose uptake was depressed at an earlier time point. These findings may contribute to a better understanding of dioxin-induced "wasting syndrome".     

Changes in plasma thyroid hormones and cortisol levels in crucian carp (Carassius auratus) exposed to the extracted microcystins

The endocrine response of crucian carp injected intraperitoneally with extracted microcystins (MC) was investigated in this study. Fish were injected intraperitoneally either with 0.75% NaCl (control) and Microcystis extract corresponding to 150 and 600 microg microcystins per kg body weight. The plasma levels of triiodothyronine (T(3)), thyroxine (T(4)), free triiodothyronine (FT(3)), free thyroxine (FT(4)), and cortisol were determined at 0, 1, 3, 12, 24, and 48h post-administration of MC-containing extract. Treated fish displayed abnormal behaviors, such as a startle response and disoriented swimming, as well as changes in ventilation rates. Plasma cortisol concentrations of fish in both dose groups significantly increased after administration of extracted MC and remained high throughout the experiment, which suggested that MC elicited a stress response in treated fish. The profiles of cortisol changes in treated fish appeared to be dose dependent, indicating that fish in the high dose group experienced greater MC-induced disturbance. Mortality occurred after 12h in the high dose group. Plasma levels of T(4), T(3), FT(4), and FT(3) did not vary significantly between the control fish. In contrast to this, fish exposed to MC-containing extract showed significant declines in T(3), FT(4), and FT(3) levels in a dose-dependent manner throughout the experiment. Plasma T(4) levels, however, did not vary significantly in the low dose group, whereas they decreased significantly at 48h post injection in the high dose group. This study demonstrates that administration of microcystins-containing extract causes a stress response and reduces the plasma levels of thyroid hormones in crucian carp. These results illustrate that microcystins exerted potent effects on the endocrine system of crucian carp, through activating their hypothalamus-pituitary- interrenal axis and disturbing thyroid function.     

Biochemical enzyme activity in different tissues of rats exposed to a novel phosphorothionate (RPR-V)

The effects of a novel phosphorothionate (RPR-V) synthesized at Indian Institute of Chemical Technology, Hyderabad, was studied using three sub-chronic doses of 0.033 (low), 0.066 (medium) and 0.099 (high) mg kg(-1) in male and female rats for a period of 90 days. This long term and repeated treatment of RPR-V revealed that the membrane bound target enzymes Aspartate aminotransferase and Alanine aminotransferase increased significantly in serum and kidney, whereas these enzymes significantly decreased in liver and lung tissues when measured after 45 and 90 days of treatment. This compound also caused significant inhibition of RBC Acetylcholinesterase, target enzyme of organophosphorus compounds revealing its effect on normal synaptic transmission. Two way Anova studies disclosed that the alterations were mostly dose and time dependent, sexual dimorphism was not observed when the activities of male rats were compared with female rats. Enzyme recoveries were recorded after 28 days of post treatment, high degree positive correlation was observed with regard to these enzymes between serum versus kidney, whereas in case of serum versus liver and lung tissues high degree negative correlation was recorded. These enzyme profiles elucidates that they increased in serum but they decreased significantly in liver and lung indicating necrosis of these tissues. However, in case of kidney the level of these enzymes increased significantly with parallel to serum, which is suggestive of an increase synthesis of these enzymes, may be an adaptive mechanism due to the stress of the toxicant. These biomarker enzymes can be detected rapidly and hence may be used for the prediction and diagnosis of pesticide insults.     

The effects of ethylene chlorohydrin on fatty acid synthesis

Male chicks weighing 700 to 900 g. received an acute or eight doses IG of 60 or 40 mg/kg ethylene chlorohydrin (ECH) respectively and were sacrificed eighteen hours after the last dose. Mitochondrial elongation of fatty acids was decreased significantly while fatty acid synthetase activity was not significantly affected by ECH treatment. Cytochrome c oxidase activity in fresh whole liver homogenate was significantly higher in chicks subjected to acute exposure with ECH when compared to the controls. Upon freezing and thawing of homogenates, cytochrome c oxidase activity increased significantly in the control group but was unchanged in the ECH group which suggests that the mitochondrial membrane integrity is compromised by the ECH treatment. Serum and liver triglyceride levels were significantly elevated in both the single and multiple ECH dose groups. Liver to body weight ratios were significantly higher in both treatment groups when compared to their controls. Histological examination of the liver of ECH-treated chicks showed cytoplasmic clearing of the cells but no vacuolization or centrilobular necrosis. Serum isocitrate dehydrogenase levels were significantly higher in the multiple treatment ECH group than in the control group.     

Effect of quinalphos on blood enzymes and its acute toxicity in bubalus bubalis

Abstract

The acute toxic effects of quinalphos (0,0‐diethyl 0–2‐quinoxalyl phosphorothioata) uere investigated in male buffalo calves. Quinalphos was administered in single oral doses of 5, 7.5, 8.5 and 10 mg/kg body wt. and its effects on erythrocyte and plasma cholinesterases, serum aspartate aminotransferase and blood glucose were studied at various time intervals. The lowest dose (5 mg/kg) produced no apparent toxic symptoms. All the animals given highest dose (10 mg/kg) died within 60–82 hours after dosing. Quinalphos at all the dose levels markedly inhibited the erythrocyte and plasma cholinesterases (68–100%) and significantly elevated the levels of serum aspartate aminotransferase and blood glucose. Seven days after the administration of quinalphos, the blood cholinesterases in survivors remained inhibited to the extent of 41–77% whereas the levels of serum aspartate aminotransferase and blood glucose were comparable to control values.     

Hexachlorophene induced alterations in brain carbohydrate metabolism of Wistar rat.

Effect of repeated oral administration of hexachlorophene (HCP) on glycolytic and oxidative pathways was studied in the rat brain. The rats were divided into three batches of six in each batch. The first batch was treated with paralytic dose (60 mg.kg-1.day-1) of HCP for 7 days. The second batch of animals was treated with sublethal dose (18 mg.kg-1.day-1) for 7 days. The third batch of animals was served as the age matched controls which received vehicle (corn oil) only. The glycolytic and oxidative metabolism of carbohydrates was significantly inhibited in the brain of rat during HCP treatment and the inhibition was more pronounced in paralytic dose treatment as compared to sublethal dose treatment. The inhibition of NADP-isocitrate dehydrogenase coupled with glucose 6-phosphate dehydrogenase indicates reduced generation of NADPH2 and pentoses for the synthesis of fatty acids and nucleotides.     

In vivo chronic effect of dimethoate and deltamethrin on rabbits

The in vivo effect of dimethoate and deltamethrin on body and organ weights, serum proteins and on plasma acetylcholinesterase (AChE), aromatic esterase and ATPase were examined in growing male rabbits throughout five months period. Both compounds had no significant effect on body weight; however, adrenal, testis & pituitary weights decreased (P less than 0.01); the liver and spleen weights increased (P less than 0.01) in a dose dependent manner. Serum total proteins and globulin decreased (P less than 0.01) in a dose dependent trend, while serum albumin was not greatly affected. AChE activity was increased (P less than 0.01) after 1 month of treatment with the two doses of dimethoate and deltamethrin; thereafter, AChE activity showed 40% inhibition of the control level. The activity of aromatic esterase increased markedly after the first month, then declined gradually until the fifth month. High dose of dimethoate markedly inhibited this enzyme particularly after the 5th month of treatment. Both doses of deltamethrin increased ATPase activity after the first month of treatment, then the ATPase activity was normal. Dimethoate inhibited ATPase particularly at the end of treatment in a dose dependent manner.     

Seveso Women's Health Study: a study of the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on reproductive health

Although reproductive effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure have been reported in numerous investigations of animals, studies of this association in humans are limited. In 1976, an explosion in Seveso, Italy exposed the surrounding population to among the highest levels of TCDD recorded in humans. The relatively pure exposure to TCDD and the ability to quantify individual level TCDD exposure from sera collected in 1976 for the Seveso cohort affords a unique opportunity to evaluate the potential dose-response relationship between TCDD exposure and a spectrum of reproductive endpoints. The Seveso Women's Health Study (SWHS) is the first comprehensive study of the reproductive health of a human population exposed to TCDD. The primary objectives of the study are to investigate the relationship of TCDD and the following endpoints: (1) endometriosis; (2) menstrual cycle characteristics; (3) age at menarche; (4) birth outcomes of pregnancies conceived after 1976; (5) time to conception and clinical infertility; and (6) age at menopause. Included in the SWHS cohort are women who were 0-40 yr old in 1976, who have adequate stored sera collected between 1976 and 1980, and who resided in Zones A or B at the time of the accident. All women were interviewed extensively about their reproductive and pregnancy history and had a blood draw. For an eligible subset of women, a pelvic exam and transvaginal ultrasound were conducted and a menstrual diary was completed. More than 95% of the women were located 20 yr after the accident and roughly 80% of the cohort agreed to participate. Data collection was completed in July 1998, serum TCDD analysis of samples for analysis of endometriosis as a nested case-control study was completed in October 1998, and statistical analysis of these data should be completed in early 1999. Serum samples are now being analyzed in order to relate TCDD levels with the remaining reproductive outcomes.     

Dioxin incinerator emissions exposure study Times Beach, Missouri

PURPOSE: To determine whether living in the vicinity of a hazardous waste incinerator that was burning material contaminated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increased TCDD and toxicity equivalencies (TEQ) in individuals living near the incinerator. METHODS: Participants were randomly chosen from an area close to the incinerator and compared to participants outside of the exposure area. TCDD and related compounds were measured in blood serum before incineration, four months after incineration started, and at the end of incineration. RESULTS: Lipid adjusted serum levels of TCDD and TEQ decreased from pre-incineration to four months after incineration, and decreased further by the end of incineration. CONCLUSION: Incineration of TCDD did not result in any measurable exposure to the population surrounding the incinerator.     

Effects of binary mixtures of six xenobiotics on hormone concentrations and morphometric endpoints of northern bobwhite quail (Colinus virginianus)

This study investigated the effects of six endocrine disrupters in five different doses (0.1, 0.3, 1, 3, 10 mg/kg or microg/kg) in ethanol administered by oral gavage to bobwhite quail eggs. Six eggs each were in each dose group of coumestrol, ethynyl estradiol, indole-3-carbinol, o,p'-DDE, p,p'-DDE, or TCDD. Eggs were also dosed in two sets. One set was ethynyl estradiol (0, 0.03, 0.1, 0.3, 1.0, 3.0, 10.0 microg/kg) and TCDD (0, 0.003, 0.01, 0.03, 0.1, 0.3 microg/kg). This set was dosed below the air cell with corn oil as vehicle. Also, northern bobwhite quail eggs were injected in ovo with nine binary mixtures of six xenobiotics prior to incubation (coumestrol (0.3 mg/kg), ethynyl estradiol (3.0 microg/kg), indole-3-carbinol (3.0 mg/kg), o,p'-DDE (1.0 mg/kg), p,p'-DDE (1.0 mg/kg), TCDD (0.1 microg/kg)). The mixtures injected were p,p'-DDE+indole-3-carbinol, coumestrol+indole-3-carbinol, TCDD+indole-3-carbinol, p,p'-DDE+o,p'-DDE, p,p'-DDE+ethynyl estradiol, coumestrol+ethynyl estradiol, coumestrol+TCDD, o,p'-DDE+ethynyl estradiol, TCDD+ethynyl estradiol. Eggs were dosed once prior to initiating incubation. Quail were allowed to hatch and were sacrificed at 21 days of age. Blood, measurements, and tissues were collected. Survival was significantly affected by increasing concentrations of TCDD in ethanol as revealed by trend analysis. Survival was also affected significantly by o,p'-DDE in ethanol but not by trend. Survival results of mixtures indicate significant differences among mixture, mixture components, and controls for coumestrol+TCDD, ethynyl estradiol+TCDD, and indole-3-carbinol+TCDD. Some trends from doses of single compounds that are supported by results in the literature were observed for hatchling weight of ethynyl estradiol dosed females, weight gain of indole-3-carbinol dosed males, weight gain and liver somatic index of o,p'-DDE dosed males, spleen somatic index of TCDD dosed males, and weight gain, gonad somatic index and egg gland somatic index of TCDD dosed females. In conclusion, the dose response treatments appeared to have effects beyond effects on survival of in ovo dosed quail. For mixtures, plasma estradiol concentrations were significantly different among coumestrol+ethynyl estradiol, ethynyl estradiol, coumestrol, and vehicle treatments. Liver somatic index among the same treatments was also significantly different. Kidney somatic index among ethynyl estradiol+p,p'-DDE, ethynyl estradiol, p,p'-DDE, and vehicle treatments was significantly different. Plasma estradiol and plasma testosterone ratios were very different among o,p'-DDE+p,p'-DDE, o,p'-DDE, p,p'-DDE, and vehicle treatments. Coumestrol and ethynyl estradiol appear antagonistic for plasma estradiol concentrations and liver somatic index when both chemicals are present together. Ethynyl estradiol and p,p'-DDE appear to act additively on kidney somatic index when combined together. Mixtures of compounds, used in this study indicate effects very different from either or both mixture components, indicating the lack of predictability of chemicals when combined in mixtures.     

Influence of ascorbic acid supplementation on the haematological and clinical biochemistry parameters of male rabbits exposed to aflatoxin B1

This study was undertaken to evaluate the effectiveness of L-ascorbic acid (AA) in alleviating the toxicity of aflatoxin B1 (AFB1) in male New-Zealand white rabbits. Five rabbits (6 months of age and mean body weight 3.12 kg) per group were assigned to 1 of 6 treatment groups: 0 mg AA and 0 mg AFB1/kg BW (control); 20 mg AA/kg BW; 15 microg AFB1/kg BW; 15 microg AFB1 plus 20 mg AA/kg BW; 30 pg AFB1/kg BW; 30 pg AFB1 plus 20 mg AA/kg BW. Rabbits were orally administered their respective doses every other day for 9 weeks, followed by a 9-week recovery period where all drugs were withdrawn. Evaluations were made for hemato-biochemical parameters and enzymatic activities. Results showed that AFB1 significantly (p < 0.05) decreased hemoglobin (Hb), total erythrocytic count (TEC) and packed cell volume (PCV), in a dose-dependent manner, and these effects were continued during the recovery period. Ascorbic acid caused an increase in these parameters, and alleviated the negative effect of AFB1 during the treatment period. Additionally, serum concentrations of total protein, albumin and glucose were significantly (P < 0.05) declined by treatment with the high dose of aflatoxin and these effects were continued during the recovery period. Ascorbic acid caused non-significant increases in these parameters and alleviated the harmful effect of AFB1. On the other hand, aflatoxin treatment caused significant increases (P < 0.05) in the activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (AlP) during the treatment period in a dose dependent manner, and this effect was continued during the recovery period, especially with the high dose. Also, treatment with the high dose of aflatoxin caused significant increases (P<0.05) in cholesterol and total bilirubin. Ascorbic acid caused significant decreases in these parameters and alleviated the harmful effects of AFB1. Whereas, Total leukocyte count (TLC), urea and creatinine were not significantly affected by aflatoxin-treatment. Generally, it is interesting feature that the treatment with AA alone had no negative effects on most of the previous parameters. Also, the presence of AA could diminished the adverse effects of AFB1 on most of hematological and biochemical values, and enzymatic activities in rabbits.     

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD)-induced down-regulation of glucose transporting activities in mouse 3T3-L1 preadipocyte

The possibility that 3T3-L1 preadipocytes, while the level of its glucose uptake activity is relatively low, may offer a useful tool for studying the cause for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced "lipolytic response" was studied. It was established first, that TCDD causes reduction of glucose uptake, one of the hallmark events of the lipolytic process. Then the function of c-Src was investigated. The antisense c-src oligonucleotide decreased the inhibitory action of TCDD on glucose uptake activity in a sequence specific manner. Since antisense oligonucleotides are known to own their blocking effects to their ability to reduce translation of proteins, Western blotting analysis was performed to verify their effectiveness. As expected, the treatment of pre-adipocytes with antisense c-src oligonucleotide reduced c-Src in a sequence specific manner. The treatment of antisense c-src oligonucleotide alone was sufficient to diminish the inhibitory action of TCDD on glucose uptake activity in 3T3-L1 cells, indicating that c-Src is somehow involved in the action of TCDD. In a similar manner, the contribution of c-Fos was investigated using antisense c-fos oligonucleotide, since c-Fos is known to be one of the most affected proteins by c-Src activation among AP-1 members. The treatment of antisense c-fos oligonucleotide did not block the effect of TCDD on glucose uptake activity in 3T3-L1 cells. Therefore, it is unlikely that c-Fos is very important in the lipolytic signal transduction of TCDD mediated through c-Src. In order to determine the relationship between c-Src and c-Myc in the mitotic signal transduction pathway, the effect of antisense c-myc oligonucleotide was investigated. Basically the same result as antisense c-src oligonucleotide experiment was obtained thereby, suggesting the importance of c-Myc as well as c-Src in the signal transduction of TCDD. To show the effect of antisense c-myc oligonucleotide treatment, the level of c-Myc protein by Western blotting and electrophoretic gel-mobility shift assay was assessed. However, antisense c-myc oligonucleotide treatment increased the activity of c-Myc in a sequence specific manner. This may be the result of cellular compensatory response to the initial suppression of c-Myc by antisense treatment. The observation that antisense c-fos oligonucleotide could not block the effect of TCDD indicates that this preadipocyte model is different from the adipocyte differentiation model.     

LIPID PEROXIDATION AND ANTIOXIDANT ENZYME ACTIVITY IN DIFFERENT ORGANS OF MICE EXPOSED TO LOW LEVEL OF MERCURY

The effects of mercuric chloride (Hg) on lipid peroxidation (LPO), glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD) and glutathione (GSH) levels in different organs of mice (CD-1) were evaluated. Mice were exposed (2 days/week) to 0.0 (control), 0.8 (low) and 8.0 (mid) and 80.0 (high) gHg/kg/day for 2 weeks. The high dose group was excluded from the study due to high mortality. LPO levels in kidney, testis and epididymus at low and mid doses; GR and GPx levels in testis at mid dose; SOD levels in brain and testis at both doses, liver and epididymus at mid dose; GSH levels in testis at both doses were significantly increased compared to their controls. However, the GR levels in kidney at both doses and in epididymus at mid dose; GPx levels in kidney and epididymus and SOD levels in kidney at both the doses; GSH levels in epididymus at mid dose were significantly decreased compared to their control. Body weight gain and food efficiency were significantly reduced (<0.05) in mid dose. These results indicated that Hg treatment enhanced LPO in all tissues, but showed significant enhancement only in kidney, testis and epididymus suggesting that these organs were more susceptible to Hg toxicity. The increase in antioxidant enzyme levels in testis could be a mechanism protecting the cells against reactive oxygen species.     

Lipid peroxidation and antioxidant enzyme activity in different organs of mice exposed to low level of mercury

The effects of mercuric chloride (Hg) on lipid peroxidation (LPO), glutathione reductase (GR), glutathione peroxidase (GPx), superoxide dismutase (SOD) and glutathione (GSH) levels in different organs of mice (CD-1) were evaluated. Mice were exposed (2 days/week) to 0.0 (control), 0.8 (low) and 8.0 (mid) and 80.0 (high) gHg/kg/day for 2 weeks. The high dose group was excluded from the study due to high mortality. LPO levels in kidney, testis and epididymus at low and mid doses; GR and GPx levels in testis at mid dose; SOD levels in brain and testis at both doses, liver and epididymus at mid dose; GSH levels in testis at both doses were significantly increased compared to their controls. However, the GR levels in kidney at both doses and in epididymus at mid dose; GPx levels in kidney and epididymus and SOD levels in kidney at both the doses; GSH levels in epididymus at mid dose were significantly decreased compared to their control. Body weight gain and food efficiency were significantly reduced (p<0.05) in mid dose. These results indicated that Hg treatment enhanced LPO in all tissues, but showed significant enhancement only in kidney, testis and epididymus suggesting that these organs were more susceptible to Hg toxicity. The increase in antioxidant enzyme levels in testis could be a mechanism protecting the cells against reactive oxygen species.     

Diazinon treatment effects on heart and skeletal muscle enzyme activities

The effect of low levels of diazinon treatment on four marker enzymes in rat heart and skeletal muscle have been investigated. Adult male Wistar rats were treated twice a week with a dose of 0.5 ml X kg-1 X day-1 diazinon for 28 weeks. Diazinon treated rats gained significantly less weight than Sham-treated controls. Typical differences in Succinate dehydrogenase (SDH), Lactate dehydrogenase (LDH), Phosphofructo kinase (PFK) and Hexokinase (HK) activities were observed between heart and skeletal muscles. Diazinon feeding had no effect on heart, soleus, gastrocnemius and plantaris SDH, LDH and PFK enzyme activities after 28 weeks. HK activity was significantly increased in sham-control soleus and plantaris muscles after 28 weeks. Diazinon feeding inhibited HK activity in plantaris muscle after 28 weeks treatment. These results demonstrate that chronic low levels of diazinon have little effect on the glycolytic and oxidative activity in heart and skeletal muscle.     

Use of cholinesterase activity in monitoring chlorpyrifos exposure of steer cattle after topical administration

The aim of this work was to study the pharmacokinetic behavior and the inhibitory effect of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities of chlorpyrifos (CPF) in steer cattle after pour-on administration. Determination of cholinesterase activity in plasma and erythrocyte was carried out according to Ellman kinetic method. CPF was analyzed by gas chromatography. AChE was the predominant form of cholinesterase analyzed, with low levels of BChE in plasma. Following the treatment with CPF, the maximum inhibitory effect on AChE or BChE were 50.88 ± 11.57 and 42.66 ± 12.01%, respectively. The chlorpyrifos plasma concentrations observed were low and they presented a high variability. Chlorpyrifos peak plasma concentration (10.42 ± 4.76 μ g/L) was reached at 8.42 ± 13.97 h. The pesticide was not detected in plasma after 48 h post treatment. The values of area under the curve (AUC) were 118.48 ± 87.46 μ g· h/L and mean resistance time (MRT) were 13.38 ± 10.41 h. The pour-on exposure to the organophosphate chlorpyrifos significantly reduced AChE and BChE activity in steer cattle and the recovery was not reached on 50 days post-treatment.     

Diazinon treatment effects on heart and skeletal muscle enzyme activities

Abstract

The effects of low levels of diazinon treatment on four marker enzymes in rat heart and skeletal muscle have been investigated. Adult male Wistar rats were treated twice a week with a dose of 0.5 ml‐kg^‐1day^‐1 diazinon for 28 weeks. Diazinon treated rats gained significantly less weight than Sham‐treated controls. Typical differences in Succinate dehydrogenase (SDH), Lactate dehydrogenase (LDH), Phosphofructo kinase (PFK) and Hexokinase (HK) activities were observed between heart and skeletal muscles. Diazinon feeding had no effect on heart, soleus, gastrocnemius and plantaris SDH, LDH and PFK enzyme activities after 28 weeks. HK activity was significantly increased in sham‐control soieus and plantaris muscles after 28 weeks. Diazinon feeding inhibited HK activity in plantaris muscle after 28 weeks treatment These results demonstrate that chronic low levels of diazinon have little effect on the glycolytic and oxidative activity in heart and skeletal muscle.