[Participation of peptide mechanisms in physiological reactions of the cardiovascular system to hyperoxia].

Experimental study in 156 white rats with renovascular hypertension, posthemorrhagic hypotension and with normal blood pressure revealed that high--ressure oxygen (303.9 kPa--50 min) could activate angiotensin--converting enzyme, the latter taking part in inactivation of endogenous opioid peptides. Involvement of peptide--like links in hemodynamic responses to hyperoxia seems to be an important component of the mechanism of oxygen action upon the cardiovascular system.