HORMONES, HORMONE RECEPTORS AND AGING.III--AGING AND HUMAN ENDOCRINE REGULATION

一项研究结果定量了衰老对调节 下丘脑-垂体-肾上腺轴已提交并发表在FY上 91. 这项工作表明，自发24小时搏动和CRH- 促肾上腺皮质激素和皮质醇刺激分泌不随年龄增长而变化， 对不同剂量的抑制，年轻人和老年人的反应相似 地塞米松。 这些数据并不支持这一假设， 另一些人认为，与年龄有关的身体成分和新陈代谢的变化是由于 下丘脑-垂体-肾上腺轴对 糖皮质激素的负反馈导致糖皮质激素过量。 我们目前正在调查生长激素缺乏与衰老的关系 并测试潜在干预措施的有效性， 内源性GH和IGF-I分泌。 24小时研究 脉冲式GH分泌、对iv GHRH的急性GH反应和血浆IGF-I 测量，在每天两次GHRH治疗两周之前和之后进行 注射，重复2个不同的剂量，已经完成了10岁， 九个年轻人。 我们证明，脉冲式GH分泌和血清IGF-I 老年男性的水平较低，并增加到正常范围内。 年轻男性每天服用2毫克GHRH后。 手稿在 准备. 一项类似的研究，研究连续24小时 老年人与年轻人的皮下GHRH输注正处于 建成 口服50：50 2周的效果研究 精氨酸/赖氨酸混合物对老年男性GH和IGF-I分泌的影响也 几乎完成。

Results of a study quantitating the effects of aging on the regulation of the hypothalamic-pituitary-adrenal axis were submitted and published in FY 91. This work showed that both spontaneous 24 h pulsatile and CRH- stimulated secretion of ACTH and cortisol were unchanged with age and responded similarly in young and old men to suppression with graded doses of dexamethasone. These data do not support the hypothesis, advanced by others, that age-related changes in body composition and metabolism are due to a loss of sensitivity of the hypothalamic-pituitary-adrenal axis to negative feedback by glucocorticoids with resultant glucocorticoid excess. We are currently investigating the relationship of GH deficiency to aging and testing the effectiveness of potential interventions for raising endogenous GH and IGF-I secretion in older people. A study of 24 hr pulsatile GH secretion, acute GH response to iv GHRH, and plasma IGF-I measurements, done before and after two weeks of twice daily GHRH injections, repeated at 2 different doses, has been completed in 10 old and 9 young men. We demonstrated that pulsatile GH secretion and serum IGF-I levels were low in older men, and increased into the range seen in normal young men after treatment with 2 mg of GHRH daily. A manuscript is in preparation. A similar study of the effects of continuous 24 h subcutaneous GHRH infusion in old vs. young men is in the final stages of completion. A study of the effects of 2 weeks of orally administered 50:50 arginine/lysine mixture on GH and IGF-I secretion in older men is also nearly complete.