Renal hypertension impairs inotropic isoproterenol effect without beta-receptor changes.
Renal hypertension impairs inotropic isoproterenol effect without beta-receptor changes.
复制标题
肾性高血压会损害正性肌力异丙肾上腺素的作用，但 β 受体不会发生变化。
DOI：
10.1152/ajpheart.1985.249.4.h814
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
H. Cingolani
中科院分区：
文献类型：
--
作者：
O. Gende;A. Mattiazzi;M. C. Camilion;P. Pedroni;C. Taquini;H. Gómez Llambí;H. Cingolani
Experiments were performed in male Wistar rats with renovascular hypertension (167 +/- 4.2 mmHg) produced by clipping the renal artery for a 3-wk period (2-kidney, 1-clip Goldblatt). The results were compared with those obtained in age-matched normotensive controls. Hypertension of 3-wk duration elicited a significant increase in ventricular weight (1.01 +/- 0.02 g) with respect to the controls (0.82 +/- 0.01 g) but had no significant effect on body weight. The inotropic responsiveness to beta-adrenergic stimulation was diminished in papillary muscles from renal hypertensive rats: the maximum increase in the maximal rate of rise of tension produced by isoproterenol was 27.39 +/- 5.4 and 11.77 +/- 2.91 g X mm-2 X s-1 (P less than 0.05) in control and hypertensive animals, respectively. Similar results were obtained when the estimated maximal velocity of shortening of the contractile element (Vmax) was used to assess myocardial contractility. The inotropic response to CaCl2 was also significantly depressed in the 2-kidney, 1-clip rats. However, the relaxant and the chronotropic responses to isoproterenol were not significantly modified in the Goldblatt rats. Assays of beta-adrenergic receptors to l-[3H]dihydroalprenolol binding, showed no significant changes in the number (expressed per mg of membrane protein) or in the affinity of the beta-receptors. These results suggest that at an early stage of the renal hypertensive model the impaired inotropic response to isoproterenol is not mediated by an alteration of the beta-receptors and should be searched at a postreceptor adenyl cyclase level.
