Taurine Ameliorates Thyroid Hypofunction and Renal Injury in L-NAME-Induced Hypertensive Rats.

There is a growing global interest in hypertension due to its associated complications including renal dysfunction in patients. The thyroid system reportedly regulates renal function in both animal and human. The present study investigated the therapeutic efficacy of taurine on renal and thyroid dysfunctions in hypertensive rats. Hypertension was induced by oral administration of nitric oxide synthase inhibitor, N-nitro L-arginine-methyl-ester (L-NAME), at 40 mg/kg body weight to the male Wistar rats for 14 consecutive days. The hypertensive rats were subsequently treated with either taurine (100 and 200 mg/kg) or reference drug atenolol (10 mg/kg) for another 14 consecutive days. Hypertensive rats showed renal damage evidenced by elevated plasma creatinine and urea levels when compared with normotensive control rats. Furthermore, L-NAME-induced hypertensive rats showed decreased circulatory concentrations of thyroid stimulating hormone, thyroxine, triiodothyronine and the ratio of triiodothyronine to thyroxine. The marked decrease in the renal antioxidant enzyme activities and nitric oxide level was accompanied by significant increase in myeloperoxidase activity and biomarkers of oxidative stress in hypertensive rats. Histological examination of kidneys from hypertensive rats revealed congestion of blood vessels, hemorrhagic lesion and disorganized glomerular structure. However, treatment with taurine or atenolol significantly reversed the suppression of thyroid function, ameliorated renal oxidative stress and histopathological lesions in L-NAME-induced hypertensive rats. Taurine may be a useful chemotherapeutic supplement in enhancing renal and thyroid functions in hypertensive patients.

Taurine enhances spermatogenic function and antioxidant defense mechanisms in testes and epididymis of L-NAME-induced hypertensive rats.

The beneficial health effects of taurine on hypertension have been demonstrated previously in both experimental and epidemiological studies. However, the role of taurine in reproductive dysfunction associated with hypertension has not been investigated. The present study evaluated the therapeutic efficacy of taurine on reproductive deficits in N-nitro-l-arginine methyl ester (L-NAME)-induced hypertensive rats. Sixty male Wistar rats were randomly assigned into six groups namely control, taurine alone, L-NAME alone (40mg/kg) or L-NAME treated with either taurine (100 and 200mg/kg) or reference drug atenolol (10mg/kg) for 28 consecutive days. Results indicated that taurine treatment significantly abrogated L-NAME-induced increase in systolic, diastolic and mean arterial pressures when compared with hypertensive control. Administration of taurine markedly increased antioxidant enzymes activities and glutathione level whereas it suppressed the increase in biomarkers of oxidative stress in the testes and epididymis of L-NAME-induced hypertensive rats. Moreover, taurine significantly reversed hypertension mediated decreases in circulatory concentrations of luteinizing hormone, follicle-stimulating hormone and testosterone whereas it increased testicular sperm number, epididymal sperm number and sperm progressive motility in the hypertensive rats. Furthermore, taurine abrogated the suppression of marker enzymes of testicular function namely acid phosphatase, alkaline phosphatase and lactate dehydrogenase and preserved the histo-architectures of the testes and epididymis in L-NAME-induced hypertensive rats. Taken together, the findings from this study highlight the beneficial role of taurine in reproductive system of L-NAME-induced male hypertensive rats. Taurine supplementation may be a good clinical approach to prevent reproductive deficits in male hypertensive patients.