Endosulfan intoxication: Blood glucose, electrolytes, Ca levels, ascsorbic acid and glutathione in rats

Persistent organic pollutants and β-cell toxicity: a comprehensive review

Persistent organic pollutants (POPs) are a diverse family of contaminants that show widespread global dispersion and bioaccumulation. Humans are continuously exposed to POPs through diet, air particles, and household and commercial products; POPs are consistently detected in human tissues, including the pancreas. Epidemiological studies show a modest but consistent correlation between exposure to POPs and increased diabetes risk. The goal of this review is to provide an overview of epidemiological evidence and an in-depth evaluation of the in vivo and in vitro evidence that POPs cause β-cell toxicity. We review evidence for six classes of POPs: dioxins, polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), organophosphate pesticides (OPPs), flame retardants, and per- and polyfluoroalkyl substances (PFAS). The available data provide convincing evidence implicating POPs as a contributing factor driving impaired glucose homeostasis, β-cell dysfunction, and altered metabolic and oxidative stress pathways in islets. These findings support epidemiological data showing that POPs increase diabetes risk and emphasize the need to consider the endocrine pancreas in toxicity assessments. Our review also highlights significant gaps in the literature assessing islet-specific endpoints after both in vivo and in vitro POP exposure. In addition, most rodent studies do not consider the impact of biological sex or secondary metabolic stressors in mediating the effects of POPs on glucose homeostasis and β-cell function. We discuss key gaps and limitations that should be assessed in future studies.

Accumulation of endosulfan in wild rat, Rattus norvegious as a result of application to soya bean in Mazoe (Zimbabwe)

An assessment of levels of endosulfan and endosulfan sulphate in rats collected from a plot sprayed with endosulfan was carried out for a period of four months. The analysis was carried out in the livers, muscles and fatty tissues of the rats using Gas Chromatography. Samples were ground with sodium sulphate and aluminium oxide and the analyte soxhlet extracted with hexane. The extract was then cleaned by florisil column chromatography. Levels of endosulfan in rats were found to range in livers from 0.356 to 5.807 ppb, in muscles from 0.089 to 5.167 ppb and in fatty tissues from 0.083 to 4.785 ppb. Levels of endosulfan sulphate correlated well with those of endosulfan and ranged in livers from 0.00 to 3.96 ppb, in muscles from 0.00 to 3.37 ppb and in fatty tissue from 0.00 to 2.93 ppb. In the control rats samples, collected from an unsprayed area in the city of Harare (University of Zimbabwe), no endosulfan could be detected.

Application of biological measures for stream integrity assessment in south-east Brazil

The sensitivity of eleven metrics using macroinvertebrate assemblages were evaluated in an environmental gradient in a tropical river in south-east Brazil. Eight sites were sampled in an altitudinal range of 160-650 m.a.s.l. during 1999 (April and August) and 2000 (February). Four substrates were sampled at each site: riffle litter, pool litter, stony substrates and sediment. Correspondence Analysis indicated that assemblages were primarily more influenced by physical changes (like deforestation and erosion processes) than the water chemistry. The sensitivity of each metric was evaluated through the application of box-and-whisker plot method by its power to assess impairment (metrics should be able to discriminate reference sites from impaired sites) and natural variability (metrics should not discriminate two reference sites). Metrics that failed in at least one of the above premises were not considered as sensitive. In this study, the most sensitive metrics were Shannon index, BMWP-ASPT, %_EPT, and relative abundance of EPT to Chironomidae.

Effects of endosulfan on B cells of Langerhans islets in rat pancreas

Endosulfan is widely used in insect control and it is absorbed by both humans and animals through ingestion, inhalation, and percutaneously. The purpose of this work was to study blood glucose levels and ultrastructural changes that might occur in the pancreas of adult male Wistar rats as a result endosulfan intoxication. The treated group (n = 60) received endosulfan orally via gavage 2.0 mg/kg per day in corn oil for 6 weeks, while the control group (n = 10) was given equal amount of corn oil for the same period. The substances were administrated once a day. Blood glucose levels were significantly increased at the end of 3rd and 4th week (P < 0.05), and 5th and 6th week (P < 0.01) after administration of endosulfan to rats compared with the control group. In electron microscopy studies, at the end of 2nd and 3rd weeks, swelling of mitochondria; at the end of 4th week, vacuoles in cytoplasm; at the end of 5th week, dissolution of mitochondrial matrix; and at the end of 6th week, picnotic nucleus in B cells in Langerhans islet were observed after endosulfan treatment.

Effects and neuro-toxic mechanisms of 2, 2', 4, 4', 5, 5'-hexachlorobiphenyl and endosulfan in neuronal stem cells

Endocrine disrupters are exogenous compounds thought to mimic the action of estrogen or other hormones and influence endocrine activity in the body (Juberg, 2000). These chemicals have adverse effects not only in the reproductive system but also in the central nervous system during development and throughout life. Polychlorinated biphenyls (PCBs) are a class of environmentally persistent and widespread halogenated hydrocarbons. It has been reported that PCBs are potential neurotoxicants. Endosulfan is an organochlorine insecticide that is extensively used to control pests in vegetables, cotton, and fruits. To determine the effect of 2, 2', 4, 4', 5, 5',-hexachlorobiphenyl(2, 4, 5-HCB) and endosulfan on embryo nervous system, we isolated neural stem cells from rat brain at embryonic day 17. Isolated neural stem cells showed pluripotenty. Stem cells could differentiate into neurons and glia. Neurite formation in endosulfan and 2, 4, 5-HCB treated cells. And it appeared to be decreased as compared with that in untreated cells. In order to know the neuro-toxic mechanisms of 2, 4, 5-HCB and endosulfan in neuronal stem cells, we investigated mitogen-activated protein kinase activity (MAPK) and gap junctional intercellular communication (GJIC). Endosulfan decreased the MAPK activity in dose dependent manner. Endosulfan and 2, 4, 5-HCB inhibited GJIC compared to the untreated cell by scrape loading dye transfer (SL/DT). 2, 4, 5-HCB and endosulfan decreased the expression of connexin 43 in dose dependent manner. These results indicated that 2, 4, 5-HCB and endosulfan may inhibit differentiation and proliferation of neural stem cells and gap junctional intercellular communication which play a crucial role in the maintenance of cellular homeostasis.

Endosulfan induces small but significant changes in the levels of noradrenaline, dopamine and serotonin in the developing rat brain and deficits in the operant learning performance

The organochlorine insecticide, endosulfan was administered (6 mg/kg body weight) to Wistar rat pups of both sexes by gastric intubation daily from post-natal days 2-25. Its effect on levels of noradrenaline (NA), dopamine (DA) and serotonin (5-HT) was assayed in olfactory bulb (OB), hippocampus (HI), visual cortex (VC), brainstem (BS) and cerebellum (CB) on days 10 and 25 using high-performance liquid chromatography (HPLC). The activity of acetylcholinesterase (AChE) was also estimated in the same regions of the brain. Performance in operant conditioning for solid food reward was assessed in 25-day-old rats. NA levels were increased in OB (12%, P < 0.01) and BS (10%, P < 0.05) at 10 days of age and in HI (20%, P < 0.01) and CB (12%, P < 0.05) at 25 days of age. DA level was decreased in HI at both 10 (42%, P < 0.001) and 25 (45%, P < 0.001) days. Serotonin levels were increased in OB (12%, P < 0.05), HI (41%, P < 0.001), VC (30%, P < 0.01) and BS (15%, P < 0.01) at 10 days of age but at 25 days, levels were decreased in BS (20%, P < 0.05) and CB (31%, P < 0.01). The activity of AChE was not different from the control groups in any of the regions studied. These data suggest that monoaminergic systems in the developing rat brain respond to endosulfan by undergoing something like a 'reorganization'. However, such changes do not ameliorate certain functional losses following the exposure to endosulfan as operant conditioning revealed deficits in acquisition as well as retention of memory.

Bioaccumulative potential and toxicity of endosulfan insecticide to non-target animals

1. Endosulfan insecticide is a polychlorinated compound used for controlling a variety of insects; it is practically water-insoluble, but readily adheres to clay particles and persists in soil and water for several years. Its mode of action involves repetitive nerve-discharges positively correlated to increase in temperature. This compound is extremely toxic to most fish and can cause massive mortalities. In fish, it causes marked changes in Na and K concentrations, decrease in blood Ca(2+) and Mg levels and inhibits Na, K and Mg-dependent ATPase (in brain). 2. Bioaccumulation of endosulfan is reported for marine animals; however, freshwater animals (e.g., crayfish) accumulate it to some extent, but they lose the compound rapidly during depuration. Endosulfan is generally less toxic to aquatic invertebrates than fish. However, it causes decreases in adenylate energy charge, oxygen consumption, hemolymph amino acids, succinate dehydrogenase, heart-beat (mussel) and altered osmoregulation. 3. Generally, mammals are less susceptible to endosulfan's toxicity than aquatic animals. The majority of studies conducted on laboratory mammals can be summarized. (a) Neurotoxicity: male rats are more sensitive than females to endosulfan, which decreases brain and plasma acetylcholinesterase activity. Endosulfan I (a metabolite) causes a significant change in norepinephrine, 5-HT and GABA. (b) Renal toxicity: inhibition of MFOs activity was noticed in rats; other effects included changes in proximal convoluted tubules and necrosis of the tubular epithelium. (c) Hepatotoxicity: chemically-induced aminopyrine N-demethylase and aniline hydrolase were found in rat liver, and reduction in the glycogen level occurred. (d) Hematologic toxicity: endosulfan exposure resulted in a significant decrease in the level occurred. (d) Hematologic toxicity: endosulfan exposure resulted in a significant decrease in the erythrocyte glutathione reductase, hemoglobin amount, RBC number and mean corpuscular volume. 4. Respiratory toxicity: involved dyspnea, acute emphysema, cyanosis and hemorrhages in teh interalveolar portions of rat's lungs. 5. Biochemical: in rats, endosulfan caused increased glucose-6-phosphate dehydrogenase activity, blood glucose level, phospholipid contents of the microsomal and surfactant system, and profoundly induced the activity of alcohol dehydrogenase and cytosolic glutathione S-transferases. It also decreased significantly Na+, K+ and Mg(2+) ATPases, plasma calcium level and alkaline phosphatase in the intestinal epithelium. 6. Immunologic toxicity: rat serum antibody titer to tetanus toxin, IgG, IgM and gammaglobulins were significantly reduced. 7. Reproductive toxicity: degenerative changes in the seminiferous epithelium, induction of the rate-limiting enzyme in testosterone production (3beta-hydroxysteroid transferase and 17 beta-hydroxysteroid transferase), histological changes in reproductive organs, testicular atrophy and the occurrence of ovarian cysts were noticed in rat. Reduction in the weight of secondary sex organ was also observed.(ABSTRACT TRUNCATED AT 400 WORDS)

Acute intoxication by endosulfan

The authors report six patients with acute endosulfan intoxication. The symptoms of nausea, vomiting, headache, and dizziness began 2.7 +/- 0.5 h after ingestion; in four cases the patients had been hospitalized but were asymptomatic. All had severe metabolic acidosis with high anion gap and hyperglycemia; five of six had decreased blood platelets. Three patients had pulmonary aspiration, and five required mechanical ventilation. The one fatality followed acute renal failure, disseminated intravascular coagulation, thrombi in the pulmonary arteries and aorta, and cardiogenic shock. In this patient the blood endosulfan was 2.85 mg/L versus a mean of 0.48 mg/L in the survivors.

The acute toxicity of endosulfan to fresh-water organisms

A static bioassay is performed for measuring the short-term (96 h) toxicity of endosulfan to juvenile catfish Clarias batrachus, insect nymph Enallagma sp. and frog tadpoles of Rana tigrina. Median Tolerance Limit, Slope Function, Confidence Limit, and Presumable Harmless Concentration were computed. The results showed that frog tadpoles are more susceptible to endosulfan than insect nymph and catfish. Morphological changes and behavioural alterations were evaluated as symptoms of endosulfan toxicity.