Jennings D B, McKirdy J C, Ohtake P J, Sarda I R, Flynn T G, Hira G K
Department of Physiology, Queen's University, Kingston, Ont., Canada.
Can J Physiol Pharmacol. 1990 Sep;68(9):1292-7. doi: 10.1139/y90-194.
We have reported that a second rat atrial natriuretic peptide, iso-rANP (1-45), as well as the putative ANP homologue, iso-rANP (17-45), elicited circulatory and renal responses in the rat similar to those found after administration of ANP. Iso-rANP also interacted with ANP to potentiate the observed biological activity in the rat. In the present studies in awake dogs, intravenous infusion of low doses (6.3-50 pmol.kg-1.min-1) of iso-rANP(1-45) and iso-rANP(17-45) increased plasma immunoreactive ANP and suppressed plasma renin activity (PRA) and aldosterone. Iso-rANP, like ring-deleted analogues of ANP, may have displaced ANP from ANP clearance receptors to increase plasma ANP concentration, since factors influencing myocardial ANP release were not changed. The effect of iso-rANP (1-45) and (17-45) in lowering PRA and plasma aldosterone may therefore have been indirect, via ANP stimulation of active guanylate cyclase-linked ANP receptors. However, an additional direct effect of iso-rANP on an active receptor cannot be excluded.
我们曾报道，第二种大鼠心房利钠肽，即异源-rANP（1-45），以及假定的ANP同源物，异源-rANP（17-45），在大鼠体内引发的循环和肾脏反应与给予ANP后所观察到的反应相似。异源-rANP还与ANP相互作用，增强了在大鼠中观察到的生物活性。在目前对清醒犬的研究中，静脉输注低剂量（6.3 - 50 pmol·kg⁻¹·min⁻¹）的异源-rANP（1-45）和异源-rANP（17-45）可增加血浆免疫反应性ANP，并抑制血浆肾素活性（PRA）和醛固酮。异源-rANP与ANP的环缺失类似物一样，可能已将ANP从ANP清除受体上置换下来，以增加血浆ANP浓度，因为影响心肌ANP释放的因素并未改变。因此，异源-rANP（1-45）和（17-45）降低PRA和血浆醛固酮的作用可能是间接的，通过ANP对活性鸟苷酸环化酶连接的ANP受体的刺激。然而，不能排除异源-rANP对活性受体的额外直接作用。
