Horiuchi M, Nishiyama H, Hama J, Takenaka T, Kondo H, Kino H, Nagata S, Sugimura K, Katori R
First Department of Internal Medicine, Kinki University School of Medicine, Osaka, Japan.
Am J Physiol. 1993 Feb;264(2 Pt 2):F286-91. doi: 10.1152/ajprenal.1993.264.2.F286.
To investigate the aldosterone responsiveness of genetically hypertensive rats, we compared characteristics of renal cytosolic aldosterone receptors from the M strain of stroke-prone, spontaneously hypertensive rats (M-SHRSP) with normotensive Wistar-Kyoto rats (WKY). In M-SHRSP, blood pressure was elevated significantly at 6 wk of age, when their plasma aldosterone concentrations were similar to those in WKY. Decreases in urine volume and sodium excretion were also observed in M-SHRSP. At 10 wk of age, M-SHRSP plasma aldosterone concentrations became significantly higher than those in WKY. On the other hand, the concentration of renal cytosolic aldosterone receptors (type I, aldosterone specific) had already increased at 6 wk of age in M-SHRSP, with no difference in affinity, and levels remained increased thereafter. There were no significant differences in molecular weights or ionic charges of either "activated" or "non-activated" aldosterone-receptor complexes between M-SHRSP and WKY, indicating that the molecular properties were similar in both groups. These results suggest that the increased concentration of aldosterone receptors in the kidneys of M-SHRSP might increase their aldosterone responsiveness and contribute to the development of high blood pressure in these animals.
为了研究遗传性高血压大鼠的醛固酮反应性，我们比较了易中风自发性高血压大鼠（M-SHRSP）的M品系和正常血压的Wistar-Kyoto大鼠（WKY）肾胞质醛固酮受体的特征。在M-SHRSP中，6周龄时血压显著升高，此时它们的血浆醛固酮浓度与WKY相似。在M-SHRSP中还观察到尿量和钠排泄减少。10周龄时，M-SHRSP的血浆醛固酮浓度显著高于WKY。另一方面，M-SHRSP在6周龄时肾胞质醛固酮受体（I型，醛固酮特异性）的浓度已经增加，亲和力无差异，此后水平持续升高。M-SHRSP和WKY之间“活化”或“未活化”的醛固酮受体复合物的分子量或离子电荷均无显著差异，表明两组的分子特性相似。这些结果表明，M-SHRSP肾脏中醛固酮受体浓度的增加可能会增强其对醛固酮的反应性，并导致这些动物高血压的发生。
