title: Nitric oxide synthase inhibition in rats: melatonin reduces blood pressure and ischemia/reperfusion-induced infarct size.
abstract: Reduction in the synthesis or bioavailability of nitric oxide plays a significant role in the development of myocardial infarction and hypertension. Numerous studies suggest that melatonin reduces blood pressure (BP) and ischemia/reperfusion (I/R) injury in rats. The effects of melatonin on the BP and I/R-induced cardiac infarct size in L-NAME-induced hypertensive rats remains unknown. This study was designed to investigate the effects of melatonin on BP and the I/R-induced infarct size in chronic nitric oxide synthase inhibited rats by L-NAME. Rats received L-NAME for 15 days to produce hypertension and melatonin the last 5 days before I/R studies. To produce cardiac damage, the left coronary artery was occluded for 30 min, followed by 120 min reperfusion. L-NAME led to a significant increase in BP. Melatonin administration (10 mg/kg) to L-NAME treated rats significantly reduced BP and infarct size. Also, melatonin attenuated the mortality resulting from I/R, but this was not statistically significant. Melatonin administration would seem important to reduce BP and infarct size resulting from I/R in L-NAME-induced hypertensive rats.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Firat University, Elazig, Turkey.
authors.forename: Esra
authors.initials: E
authors.lastname: Deniz
authors.forename: Engin
authors.initials: E
authors.lastname: Sahna
authors.forename: Hakki Engin
authors.initials: HE
authors.lastname: Aksulu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D006973:Hypertension / Q000139:chemically induced / Q000188:drug therapy*; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D023421:Models, Animal; D009203:Myocardial Infarction / Q000188:drug therapy; D017202:Myocardial Ischemia / Q000188:drug therapy* / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000188:drug therapy*; D019331:NG-Nitroarginine Methyl Ester; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000975:Antioxidants; D019001:Nitric Oxide Synthase; D008550:Melatonin; D019331:NG-Nitroarginine Methyl Ester