大鼠肾脏中抗利尿激素受体的个体发生发育：激素结合与腺苷酸环化酶激活的比较

Ontogenic development of antidiuretic hormone receptors in rat kidney: comparison of hormonal binding and adenylate cyclase activation.

作者信息

Rajerison R M, Butlen D, Jard S

出版信息

Mol Cell Endocrinol. 1976 Mar;4(4):271-85. doi: 10.1016/0303-7207(76)90061-7.

Abstract

The development of adenylate cyclase responsiveness to vasopressin and parathyroid hormone was studied using membrane fractions prepared from medullo-papillary and cortical portions of kidneys of 2-46-day-old rats. The development of vasopressin binding capacity was followed on the same preparations, using [3H]vasopressin. The characteristics of medullo-papillary adenylate cyclase response to vasopressin were identical in young and adult control animals as regards apparent Km values for [Lys8]vasopressin (3 X 10(-8) M), specificity towards the natural neurohypophysial peptides and the effects of Mg2+. However, the magnitude of maximal enzyme activation by vasopressin was much lower in very young than adult animals. Accordingly vasopressin responsiveness increased sharply between the 10th and 25th days but the magnitude of the maximal response only reached the adult value between the 30th and 45th days after birth. During both periods basal adenylate cyclase activity was almost independent of age. Specific vasopressin binding sites were detected on kidney medullo-papillary membranes from young animals. Vasopressin binding capacity and adenylate cyclase responsiveness to the hormone followed similar development patterns. However, the appearance of specific binding sites slightly preceded the onset of adenylate cyclase responsiveness. Basal cortical adenylate cyclase activity/mg protein was 12 times higher in 2-day-old rats than in the adult controls. It dropped with age but only fell to the adult value between the 25th and the 35th days after birth. For the youngest animals tested (2 days old), the increase in activity due to parathyroid hormone was about half the increase measured in adults, and gradually rose to about 75% of the adult response between the 2nd and 46th days after birth. Apparent Km values for parathyroid hormone were identical in young and adult animals (3.2 and 3.0 U/ml, respectively).

摘要

利用从2至46日龄大鼠肾脏的髓质乳头和皮质部分制备的膜组分，研究了腺苷酸环化酶对血管加压素和甲状旁腺激素反应性的发育情况。使用[3H]血管加压素，在相同的制剂上追踪血管加压素结合能力的发育情况。在幼年和成年对照动物中，髓质乳头腺苷酸环化酶对血管加压素的反应特征在[Lys8]血管加压素的表观Km值（3×10(-8)M）、对天然神经垂体肽的特异性以及Mg2+的影响方面是相同的。然而，幼年动物中血管加压素激活酶的最大程度远低于成年动物。因此，血管加压素反应性在第10天至第25天之间急剧增加，但最大反应程度仅在出生后第30天至第45天之间达到成年值。在这两个时期，基础腺苷酸环化酶活性几乎与年龄无关。在幼年动物的肾脏髓质乳头膜上检测到了特异性血管加压素结合位点。血管加压素结合能力和腺苷酸环化酶对该激素的反应性遵循相似的发育模式。然而，特异性结合位点的出现略早于腺苷酸环化酶反应性的开始。2日龄大鼠皮质基础腺苷酸环化酶活性/毫克蛋白比成年对照高12倍。它随年龄下降，但仅在出生后第25天至第35天之间降至成年值。对于测试的最年幼动物（2日龄），甲状旁腺激素引起的活性增加约为成年动物测量值的一半，并在出生后第2天至第46天之间逐渐升至成年反应的约75%。幼年和成年动物甲状旁腺激素的表观Km值相同（分别为3.2和3.0 U/ml）。