[Study of the mechanism of hypertensive effect of FMRF-like peptides]

The effect of several synthetic FMRF-like peptides in hemodynamics and tonus of isolated rat vessels was studied. Peptide pGlu-Aps-Pro-Phe-Leu-Arg-Phe-NH2 and its C-terminal fragment Arg-Phe-NH2 induced i.v. short-term increase in arterial blood pressure and heart rate in narcotized rats. Benzpgexonium could reduce both effects of the drug. The peptide effect on blood pressure could be neutralized by prazosin; tachycardia could be prevented by propranolol. The studied peptide and its C-end tetra-, penta- and dipeptide produced relaxation of isolated rat aorta toned by prostaglandin F2 alpha. It is supposed that hypertensive effect of FMRF-like peptides is realized through central mechanisms.