Cardiovascular Actions of Physalaemin

Abstract

Physalaemin and eledoisin and perhaps substance P belong to a group of peptides having similar pharmacological actions (Bertaccini et al., 1965a,b) both in vitro and in vivo. In vivo, these peptides affect the systemic arterial blood pressure in a similar way, but physalaemin is two to four times more active than eledoisin in decreasing blood pressure in dogs and increasing it in chickens. As previously reported, both the increase of blood flow and the ypotension provoked by eledoisin in several animal species, including man, could be explained by the peripheral vasodilating property of this peptide. Therefore, since physalaemin seemed to be closely related to eledoisin, we decided to investigate the peripheral vascular effects of physalaemin as well. In addition, since we had no data for proving whether the dilator action of eledoisin on vascular beds was a direct or an indirect action via the peripheral nervous system, we performed experiments on denervated vascular beds and made comparisons with other vasodilator drugs.