Abstract: | As the data on estimation of adenylate cyclase activity in the aortic and nephric tissue have demonstrated the product of histochemical reaction is localized in sarcolemmic vesicles of the aortic wall smooth muscle and on the plasmic membrane of the brush border microvilli in the proximal tubules of the kidney. From our knowledge on how some hormones affect the cell via the intracellular mediator cAMP, which is formed from Atp at activation of the adonylate cyclase system, it is possible to suggest that sarcolemmic vesicles of the smooth muscle cells and separate parts in plasmolemma of the brush border of the proximal tubules correspond to the adenylate cyclase system in the receptory zones where the hormones interact with the cell. It is interesting to note topographic coincidence in one ultrastructure--sarcolemmic vesicules--of the adenylate cyclase system and a sarcolemmic area through which calcium ions (the primary regulator of contractility) are excreted at relaxing action of beta-adrenergetics on the smooth muscles. |