HORMONES AND AGING--HYPOTHALAMIC-PITUITARY FUNCTION IN EXPERIMENTAL ANIMALS

许多激素分泌和组织对激素的反应依赖于 细胞膜受体转导在老年动物中是钝化的， 与年轻的动物相比。 荷尔蒙反应的这种变化是 通常是由于刺激的水平或比率的改变， GTP结合蛋白（Gs）和抑制性GTP结合蛋白（Gi）， 介导许多细胞内的膜结合受体反应。 我们有 一直在研究衰老对G蛋白的影响， 脂肪细胞环化酶介导的儿茶酚胺受体的组分， 肝细胞膜，最近，已经开始研究 增龄对骨骼肌和其他组织对生长激素反应的影响 而睾酮则集中在EF-1 α上，这是一种G蛋白， 核糖体中蛋白质合成的介体。过去的活动 一年来主要致力于方法的开发和优化， 环化酶介导的G蛋白复合物、EF-1 α mRNA的新测定法 检测基因激活和组织中的EF-1 α蛋白。

Many hormone secretion and tissue responses to hormones that depend on cell membrane receptor transduction are blunted in old animals when compared to young animals. Such changes in hormonal responses are frequently due to alterations in the levels or ratios of stimulatory GTP-binding proteins (Gs) and inhibitory GTP binding proteins (Gi ) which mediate many membrane-bound receptor responses intracellularly. We have been conducting investigations of the effects of aging on the G-protein components of cyclase mediated catecholamines receptors in fat cell and hepatic cell membranes, and, more recently, have initiated studies of the effects of aging on responses of skeletal muscle and other tissues to GH and testosterone concentrating on EF-1alpha, a G protein which is a key mediator of protein synthesis at the ribosome. Activities in the past year have been devoted mainly to methods development and optimization of new assays for cyclase mediating G-protein complexes, for EF-1alpha mRNA to detect gene activation, and for EF-1alpha protein in tissue.