Effect of eledoisin, physalaemin and some eledoisin- or physalaemin-like peptides on water intake and arterial blood pressure in conscious pigeons

Abstract

Summary The hypotensive and dipsogenic effects of eledoisin, physalaemin and some synthetic eledoisin- or physalaemin-like peptides were studied in conscious pigeons, respectively after intravenous or intracerebroventricular administration. The effects of the peptides were compared to the hypotensive or dipsogenic activities of eledoisin considered equal to 100. o 1) Shortening of eledoisin molecule by means of progressive elimination of up to four N-terminal aminoacid residues left practically unmodified the dipsogenic effect, while it progressively reduced the hypotensive effect. 2) Physalaemin was a dipsogen as potent as eledoisin, but its hypotensive activity was approximately double the one of eledoisin. 3) Modifying of physalaemin molecule produced different alterations in the dipsogenic and hypotensive effect. Apparently there was no relationship between the dipsogenic and the hypotensive effect of the substances tested.