Ivanova L N, Melidi N N
Institute of Cytology and Genetics, Siberian Branch of RAS, Novosibirsk.
Ross Fiziol Zh Im I M Sechenova. 1999 Jun;85(6):847-56.
Involvement of enzymes catabolizing hyaluronic acid (hyaluronidase, beta-glucuronidase, N-acetyl-beta-D-hexosaminidase) in the hydroosmotic action of vasopressin on the amphibian urinary bladder Rana Ridibunda was studied. It was found that vasopressin (50 nM), agonist of V2 receptors dDAVP (1.5 mcM) and forscolin (30 mcM) induce an activation of enzymes and its release into the Ringer solution at the mucosal surface simultaneously with the increase in the osmotic water flow. Maximal effect was observed 10 min later than hydroosmotic response. Release of enzymes under vasopressin effect was found in the absence of osmotic gradient and water flow through the epithelium. The repeated substitution of the outer Ringer solution for the fresh one resulted in the increase in the both the water permeability and the release of enzymes through the mucosal surface. We suggested that involvement of hyaluronate-hydrolases in the vasopressin effect is mediated by the cAMP-dependent mechanism. It is supposed that this effect creates conditions for the increase in the permeability of glycosaminoglycan structures covering adjacent to the apical cell surface.
研究了分解透明质酸的酶（透明质酸酶、β-葡萄糖醛酸酶、N-乙酰-β-D-己糖胺酶）在血管升压素对两栖动物林蛙膀胱的水渗透作用中的参与情况。发现血管升压素（50 nM）、V2受体激动剂dDAVP（1.5 μM）和福斯可林（30 μM）在渗透水流量增加的同时，诱导酶的激活并将其释放到黏膜表面的林格液中。酶释放的最大效应比水渗透反应晚10分钟出现。在没有渗透梯度且水不流经上皮的情况下，发现血管升压素作用下有酶的释放。用新鲜的林格液反复替换外部林格液会导致水通透性和通过黏膜表面的酶释放量均增加。我们认为透明质酸水解酶参与血管升压素效应是由cAMP依赖性机制介导的。据推测，这种效应为增加覆盖在顶端细胞表面附近的糖胺聚糖结构的通透性创造了条件。
