Comparative antihypertensive activities of losartan and HM70186 in rats with hepatic dysfunction.

HM70186, a medoxomil ester of EXP3174 which is an active metabolite of angiotensin II receptor blocker losartan, was synthesized, and its antihypertensive efficacy was evaluated in rats with hepatic dysfunction. Male Wistar rats were intraperitoneally injected with 0.5 mL/kg of carbon tetrachloride to cause hepatic injury, and implanted with an osmotic minipump containing angiotensin II (0.4 mg/kg/day) to induce hypertension. After confirmation of both hepatic damage and hypertension, the rats were orally administered losartan or HM70186, and then blood pressure and heart rate were monitored for 24 h. In normal animals, angiotensin II-induced hypertension was lowered by losartan, resulting in an ED(-30 mmHg) of 9.05 mg/kg. HM70186 also immediately decreased the blood pressure in a dose-dependent manner, exhibiting an ED(-30 mmHg) of 0.89 ng/kg (10,000 times the potency observed with losartan). Moreover, HM70186 (3 ng/kg) exerted a strong antihypertensive effect even in rats with hepatic injury, while losartan (10 microg/kg) was ineffective. These results suggest that HM70186 could be a promising candidate for the treatment of hypertension accompanied by hepatic dysfunction.

trans-Resveratrol relaxes the corpus cavernosum ex vivo and enhances testosterone levels and sperm quality in vivo.

We examined the effects of trans-resveratrol on male reproductive functions; ex-vivo penile erection and in-vivo sperm counts and quality. For the ex-vivo study, the relaxation effects of resveratrol on isolated New Zealand white rabbit corpus cavernosum, precontracted by phenylephrine (5x10(-5) M) were measured. The in-vivo study measured reproductive organ weights, blood testosterone levels, testicular histopathology, sperm counts, as well as the epididymal sperm motility and deformity of male ICR mice given an oral dose of resveratrol (50 mg/ kg) for 28 days. Resveratrol elicited a concentration-dependent relaxing effect on corpus cavernosum, leading to a median effective concentration (EC50) of 0.29 mg/mL. Repeated treatment with resveratrol (50 mg/kg) did not cause an increase in body weight, reproductive organ weight or testicular microscopic findings; however, resveratrol did elicit an increase in blood testosterone concentration, testicular sperm counts and epididymal sperm motility by 51.6%, 15.8% and 23.3%, respectively, without influence on sperm deformity. In conclusion, we propose that resveratrol has a positive effect on male reproductive function by triggering a penile erection, as well as enhancing blood testosterone levels, testicular sperm counts, and epididymal sperm motility.