beta-adrenergic receptor and adenylate cyclase in transverse tubules of skeletal muscle.
beta-adrenergic receptor and adenylate cyclase in transverse tubules of skeletal muscle.
复制标题
骨骼肌横管中的β-肾上腺素能受体和腺苷酸环化酶。
DOI：
10.1016/s0021-9258(17)40801-5
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
M. García
中科院分区：
文献类型：
--
作者：
A. Caswell;S. Baker;H. Boyd;L. Potter;M. García
实验旨在阐明-肾上腺素能激动剂在骨骼肌微粒体中的作用部位。微粒体分成纵向网状、末端池状和分离的横向小管。横小管选择性地用[3H]沃巴因标记和跟踪。通过[3H]二氢阿普萘洛尔结合鉴定β -肾上腺素能受体。β -肾上腺素能受体、腺苷酸环化酶和蛋白激酶刺激磷酸化检测结果显示：1)β -肾上腺素能受体在横小管中检测到，受体密度为0.61 pmol/mg蛋白。在纵向网或末端池中未检测到明显的结合。2)异丙肾上腺素刺激的腺苷酸环化酶存在于微粒体中，但同样局限于横向管状部分。横小管F刺激环化酶活性为2.3 nmol/mg蛋白/min。3)未检测到环AMP和蛋白激酶对微粒体的磷酸化作用。我们得出结论，肾上腺素对骨骼肌的作用是通过外膜的受体和腺苷酸环化酶介导的。
Experiments were carried out to clarify the sites of action of beta-adrenergic agonists in skeletal muscle microsomes. Microsomes were fractionated into longitudinal reticulum, terminal cisternae, and isolated transverse tubules. Transverse tubules were selectively labeled and tracked with [3H]ouabain. beta-adrenergic receptor was identified by [3H]dihydroalprenolol binding. Assays of beta-adrenergic receptor, adenylate cyclase, and protein kinase-stimulated phosphorylation showed: 1) beta-adrenergic receptor was detected in transverse tubules with a receptor density of 0.61 pmol/mg of protein. No significant binding was detected in longitudinal reticulum or in terminal cisternae. 2) Isoproterenol-stimulated adenylate cyclase was present in microsomes but was similarly confined to the transverse tubular fraction. The activity of F- stimulated cyclase in transverse tubules was 2.3 nmol/mg of protein/min. 3) No phosphorylation of microsomes by cyclic AMP and protein kinase could be detected. We conclude that the action of epinephrine on skeletal muscle is mediated through receptors and adenylate cyclase in the external membrane.