Endothelin-1 induced alterations in oxidative-nitrosative stress markers

OBJECTIVE: The aim of this preliminary study is to investigate the effects of exogenous Endothelin-1 (ET-1) on systolic blood pressure and heart rate as well as on plasma nitric oxide metabolites, malondialdehyde, copper and zinc concentrations and red cell superoxide dismutase and catalase activities.

METHODS: Thirty Wistar-Albino male rats, 8-10 weeks old, with a mean body weight of 285 gm were used in the study. Daily systolic blood pressures were measured by tail plethysmography. Following exogenous administration of ET-1 (1 nmol/kg) systolic arterial blood pressures were recorded and blood samples of control and experimental groups were drawn. Nitric oxide metabolites (nitrite, nitrate), malondialdehyde, copper, zinc concentrations in plasma, superoxide dismutase and catalase activities and copper, zinc concentrations in red cell were determined both in control and experimental groups. All laboratory procedures were performed at the Department of Pathophysiology, School of Medicine, Ankara University, Ankara, Turkey in 2003.

RESULTS: There were statistically significant increases in plasma nitrate, red cell superoxide dismutase activity, systolic arterial blood pressure and statistically significant decreases in red cell catalase activity, plasma copper, red cell zinc concentrations in experimental group due to exogenous ET-1 administration compared to controls.

CONCLUSION: There appears an important interaction between exogenous ET-1 and oxidative-nitrosative stress markers which may affect the progression of hypertension.