肾上腺升压素的血管活性及其与肾上腺髓质素的相互作用

本研究发现１０和１００ｎｍｏｌ／Ｌ肾上腺升压素（ａｄｒｅｎｏｔｅｎｓｉｎ，ＡＴ）呈剂量依赖性增加大鼠主动脉环张力（Ｐ＜００１）；２．５ｎｍｏｌ／ｋｇ　ＡＴ静脉推注可使麻醉大鼠平均动脉压升高２８％（Ｐ＜０．０１）；１００ｎｍｏｌ／Ｌ可使培养的大鼠血管平滑肌细胞的３Ｈ－胸腺嘧啶核苷参入量增加５５％（Ｐ＜０．０１）；肾上腺髓质素（ａｄｒｅｎｏｍｅｄｕｌｌｉｎ，ＡＭ）则在不同程度上抑制ＡＴ的上述活性；１、１０和１００ｎｍｏｌ／ＬＡＴ可分别抑制ＡＭ的释放率达１９％、３５％和４６％（Ｐ＜０．０５或０．０１），而１０ｎｍｏｌ／ＬＡＭ也是一种新的缩血管、升血压和促进血管平滑肌增殖的多肽；ＡＴ与ＡＭ之间在血管活性上相互拮抗，在释放上交互抑制，这些相互作用可能是肾上腺髓质素原的分子内调节的体现。

Vasoactive effects of adrenotensin and interactions between adrenotensin and adrenomedullin

Our study found that: 10 and 100 nmol/L adrenotensin (ADT ) augmented rat aortic tension in a dosedependent manner (P<0.01 ): an intravenous bolus injection of ADT (2.5nmol/kg) increased mean arterial pressure (MAP) offanesthetized rat by 28% (p<0.01 ); 100 nmol/L ADY increased 3H-thymidine incorporation in cultured rat vascular smooth muscle cell (VSMC ) by 55% (P<0.01 ): adrenomedullin (ADM ) inhibited these activities of ADT in different degrees: ADT at dose of decreased 1, 10 and 100 nmol/L ADM release rate by 19% 35% and 46%, respectively (P<0.05 or 0.01 ) and 10 nmol/L ADM also inhibited ADT release by 45% from rat aorta (P<0.01). These data suggested that ADT might be a novel peptide that have the activities ofvasoconstriction, pressor and inducing VSMC proliferation: there are antagonistic effects in vascular activities and reciprocal inhibition in release regulation between ADT and ADM; and these interactions may be the manifestations of intramolecular regulation of proadrenomedullin.