Effects of endothelin A receptor antagonist BQ123 on femoral artery pressure and pulmonary artery pressure in broiler chickens.

摘要

Endothelin-1 (ET-1) is an important factor in regulation of cardiovascular tone in humans and mammals, but the biological function of ET-1 in the avian vascular system has not been determined. The study was conducted to determine the role of endogenous ET-1 in the vascular system of poultry by investigating the effect of endothelin A receptor (ET< sub>AR) antagonist BQ123 on the femoral arterial pressure (FAP) and pulmonary arterial pressure (PAP) of broiler chickens. Results revealed that both plasma and lung homogenate ET-1 levels increased with age over the seven weeks life cycle of broiler chickens. It was observed that the FAP and PAP significantly decreased after 60 min of intravenous injection of BQ123 at 0.4 micro g/kg and 2.0 micro g/kg (p<0.05). The chronic infusion of BQ123 at 2.0 micro g/kg twice a day into the abdominal cavities led to a significant decreased in systolic pressure of the femoral (p<0.05) and pulmonary arteries (p<0.01) of broiler chickens after 7 and 14 days of treatment. It is suggested that ET< sub>AR antagonist BQ123 significantly decrease FAP and PAP and that endogenous ET-1 is involved in the maintenance and regulation of systemic and pulmonary pressure in broiler chickens.