Incubation and perfusion of isolated rat aorta and radioimmunoassay of adrenomedullin(AM) and adrenotensin(AT) in the media were used to investigate the factors which influence the release of AM and AT from rat aorta. We found that: ①angiotensin Ⅱ(A Ⅱ) and endothein-1(ET-1) at doses of 1 - 100 nmol/m increased AM release rate in a dose-dependent mariner; 1 and 10 nmol/L AⅡ and ET-1 had no obvious effects on AT release

100 nmol/L A Ⅱ and ET-1 increased AT release rate; the six AM/AT ratios increased; ② 10 nmoll epinephrine augmented release rates of AM and AT and 10nmol/L calcitonin gene related peptide(CGRP) decreased the release rate same degree; the two AM/AT ratios were not changed; ③ Iμ/ml lipopolysaccharide(LPS) had no effect on the release rates; but 5 and 10μ g/ml LPS increased release rates of AM and AT and the AM/AT ratios; ④ Hypoxia inhibited only AT release

thus increasing the AM/AT ratio; ⑤ Increase of flow rate augmented release rates of AM and AT

but did not change their ratio; decrease of flow rate had no effect on their release rates. These data suggest that A Ⅱ

ET-1

epinephrine

CGRP

LPS

oxygen supply and flow tale may be the factors participating in the regulation of AM and AT release from rat aorta.