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

在对脑垂体细胞膜信号转导的研究中，我们观察到 对于与年龄相关的GTP监管单位水平的变化，使用 针对GalphaS、Galphai1&2、Galphai3、Galphaq和 β亚基。没有发现由于年龄的原因而发生的显著变化。 GalphaS的。在β-亚基水平上看到了显著的变化 (35K)，超过36K(9：1)。重要的是要考虑 β亚基的水平，因为现在很明显，它们调节 α-亚基活性不发生变化，激活K+ 可能对钙离子通道产生直接或间接的影响。 与年龄相关的Galphai3水平显著下降，GTP 假定抑制腺酰环化酶的调节亚单位，以及一个 Galphaq的水平显著增加，这与 磷脂酶C的激活，这是产生IP3和二酰甘油的酶 荷尔蒙释放所必需的。在一项关于年龄影响的新倡议中 我们克隆了一种动物模型对生长激素和睾酮的组织反应 并成功地使用标记的cDNA探针对EF1-α的mRNA进行了定量 在肌肉和其他组织中使用Northern blotting和IGF-I的mRNA 核糖核酸酶保护试验检测IGF-I受体。10岁和10岁以下的小鼠 31个月，每天治疗5天或10天，杀死，并组织 保存完好。已完成肌肉、肝脏和肾脏的RNA提取 对特定信使核糖核酸的量化工作已经开始。总RNA(更正为 蛋白质或组织湿重)和体重在 与年龄匹配的安慰剂对照组进行比较。

In studies of pituitary cell membrane signal transduction, we have looked for age-related changes in the levels of GTP regulatory units using specific antibodies against GalphaS, Galphai1&2, Galphai3, Galphaq, and beta-subunits. No significant changes due to age were found in the levels of GalphaS. Significant changes are seen in the levels of beta-subunit (35K) which predominates over the 36K (9:1). It is important to consider the levels of the beta-subunits since it is now clear that they regulate alpha-subunit activity without changes in alpha-subunit levels, activate K+ channels, and possibly have an effect, direct or indirect on Ca++ channels. There was a significant age-related decrease in levels of Galphai3, the GTP regulatory subunit that putatively inhibits adenylyl cyclase, and a significant increase in the levels of Galphaq which is involved in the activation of phospholipase C, the enzyme generating IP3 and diacylglycerol required for hormone release. In a new initiative on the effects of age on tissue responses to GH and testosterone in an animal model, we have cloned and successfully used labeled cDNA probes to quantify mRNA's for EF1-alpha in muscle and other tissues using Northern blotting and mRNA's for IGF-i and IGF-I receptor using the RNA'ase protection assay. Mice of ages 10 and 31 months have been treated daily for 5 or 10 days, killed, and tissues preserved. RNA extractions have been completed on muscle liver and kidney and quantification of specific mRNA's has begun. Total RNA (corrected for protein or tissue wet weight) and body weight were shown to increase in the treated mice, compared with age-matched placebo controls.