Partially Purified Bovine Atrial Fraction on Animal Kidney, Smooth Muscle and Sodium Transport in Toad Skin

Abstract

The potent diuretic, natriuretic, vasorelaxant and endocrine effects of atrial natriuretic peptides isolated from several mammals (rat, monkey, pig, man) have been extensively investigated (1–5) and this knowledge is being applied in the treatment of cardiorenal disease (6, 7). The evidence as to the mechanisms underlying these effects is still incomplete (5). In an attempt to establish the existence and actions of a natriuretic factor we assayed the biological activity of a partially purified fraction isolated in our laboratory from bovine heart atria (AF) on diuresis and natriuresis in the anaesthetised dog, on mammalian vascular smooth muscle, small intestine, on the rate of active sodium transport in isolated toad skin, and on the response of the skin to aldosterone and to angiotensin II (Agt II). The action of synthetic atrial natriuretic peptide (Atriopeptin III, ANP) on the isolated toad skin was also examined.