Correlation of testicular toxicity and oxidative stress induced by chlorpyrifos in rats.

Effect of chlorpyrifos pesticide on testicular oxidative damage was studied in Sprague-Dawley rats at varying doses. At lower doses (5 and 10 mg/kg body weight/30 days), reduction in plasma levels of testosterone and follicular stimulating hormone (FSH) and luteinizing hormone (LH) along with significant shrinkage of seminiferous tubules and drastic changes in germ cells were seen. But these adverse changes of testes were restored with the revival of serum testosterone and FSH and LH at higher doses (20 and 30 mg/kg body weight/30 days). Similarly, levels of testicular lipid peroxidation and diene conjugates were elevated whereas activities of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase), steroidogenic (Δ(5), 3ß-HSD and Δ(5), 17ß-HSD) enzymes and angiotensinogen-converting enzyme and glutathione content including lipid-protein content of testes were decreased at low doses. But at higher doses, reductions in level of lipid peroxidation (as revealed by malondialdehyde [MDA] value) and conjugated dienes were found and on the contrary, revivals of testicular antiperoxidative/antioxidant enzymes defense systems, angiotensinogen-converting enzyme (ACE), steroidogenic enzymes, lipid-protein and antioxidant glutathione content were observed. Therefore, the present study indicated from the results that chlorpyrifos had a dual effect at both doses on oxidative stress changes, but at higher doses, the cells were triggering its natural defense mechanism to combat the insult of lower doses of chlorpyrifos and became operative possibly through corrective measure of antioxidant enzymes defense system and pituitary gonadotropins hormones feedback mechanisms on testes.

Effect of delta-9-tetrahydrocannabinol on altered antioxidative enzyme defense mechanisms and lipid peroxidation in mice testes.

The present study examined the adverse effects of delta-9-tetrahydrocannabinol (i.p injection in albino mice) on free radical damage of testicular lipids (lipid peroxidation) at low doses and the role of antioxidant enzymes defense system at high dose and particularly at the withdrawal of the drug after applying higher dose (recovery dose). At lower doses (total doses ranging from 6 mg to 28 mg), there was a significant increase of lipid peroxidation and decrease in testicular lipid content. But the effects were slightly lowered at high dose (total dose 70 mg) and at the withdrawal of the drug (recovery dose). Similarly, marked decrease of antioxidant enzyme systems (superoxide dismutase, catalase, and glutathione peroxidase) and glutathione content were noticed at low doses. But the effects were slightly higher at high dose and at the withdrawal of the drug. Similarly, low-dose treatments caused significant shrinkage of tubular diameter and detrimental changes in seminiferous epithelium of testis resulting in lowered plasma testosterone and pituitary gonadotropins (follicular stimulating and luteinizing hormone levels. But at high dose and particularly at withdrawal of the drug, regression of seminiferous tubules and recovery of various germ cell layers of testes through the revival of testosterone hormone and pituitary gonadotropins were observed.