[Cardiovascular responses to microinjection of atrial natriuretic peptide into ventrolateral medulla of rat].

Application of atrial natriuretic peptides (alpha-ANP and AP III) to glutamate sensitive area of ventrolateral medulla produced a dose-dependent decrease in MAP and HR in anesthetized rats. Lower dosage of AP III induced hypotension without bradycardia, whereas the higher dosage of AP III decreased both blood pressure and heart rate. The results suggested that ANP may inhibit the medullary sympathetic center.