Nikodijevic O, Nikodijevic B, Zinder O, Yu M Y, Guroff G, Pollard H B
Proc Natl Acad Sci U S A. 1976 Mar;73(3):771-4. doi: 10.1073/pnas.73.3.771.
Adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] activity of purified secretory vesicle membranes from the adrenal medulla is inhibited by I-isoproterenol and I-epinephrine, as well as by nerve growth factor (NGF). The effect of these agents was found to be dose-dependent and, in the case of the catecholamines, saturable. NGF was active at concentrations as low as 10(-8) M. Oxidized NGF was only minimally active, and insulin was completely inactive. Neither dopamine nor phenylephrine had activity. Inhibition of cyclase by either isoproterenol or epinephrine was blocked by I-propranolol, a specific beta-antagonist, but propranolol by itself had no effect on adenylate cyclase activity. The data indicate that the secretory vesicle membrane has beta-adrenergic receptors coupled to the adenylate cyclase. Propranolol was also found to block the NGF-induced inhibition of cyclase. We conclude that the granule membrane has beta-adrenergic receptors as well as NGF-reactive sites, and that the two may be functionally linked.
肾上腺髓质纯化分泌囊泡膜的腺苷酸环化酶[ATP焦磷酸裂解酶(环化), EC 4.6.1.1]活性受到异丙肾上腺素、肾上腺素以及神经生长因子(NGF)的抑制。发现这些药剂的作用呈剂量依赖性,就儿茶酚胺而言呈饱和性。NGF在低至10(-8)M的浓度下具有活性。氧化型NGF仅有微弱活性,而胰岛素则完全无活性。多巴胺和去氧肾上腺素均无活性。异丙肾上腺素或肾上腺素对环化酶的抑制作用被特异性β拮抗剂普萘洛尔阻断,但普萘洛尔本身对腺苷酸环化酶活性无影响。数据表明,分泌囊泡膜具有与腺苷酸环化酶偶联的β-肾上腺素能受体。还发现普萘洛尔可阻断NGF诱导的环化酶抑制作用。我们得出结论,颗粒膜具有β-肾上腺素能受体以及NGF反应位点,且二者可能在功能上相联系。