A Potent Hypotensive Factor in Chicken Left Ventricle

AbstractChicken artria and ventricles both have membrane-bound granules which resemble those containing atriopeptin.(ANP) in mammals. However, nothing is known about the contents of the avian granules. A previous study in chickens showed that although extracts of whole chicken heart or synthetic rat ANP both caused profound hypotension, ANP caused both natriuresis and diuresis, while chicken heart extract did not. The present study sought to locate the region(s) of chicken heart containing the hypotensive activity, and to observe the effect on sodium and water excretion and blood pressure in rats. Acid extracts of either atrium, either ventricle, ventricular septum, skeletal muscle, and liver were identically prepared from chickens and rats. Extracts were adjusted to the same protein concentration and injected (0.15 ml/kg) into anesthetized Single Comb White Leghorn roosters. Mean arterial pressure (MAP) and the time for recovery were measured. The most potent extract from chicken hearts was from the left...