MECHANISMS OF PULSATILE GROWTH HORMONE (GH) SECRETION IN HUMANS

生长激素(GH)的分泌是搏动性的。生长激素脉冲的产生机制尚不清楚。可能的解释包括生长激素释放激素(GHRH)的脉动性分泌，生长抑素(SRIH)的周期性下降，两者的结合，或者其他中枢神经内分泌调节分子/因素的参与。我们以前的研究表明，GHRH是脉动性GH释放所必需的。然而，有可能GHRH只是允许的，SRIH的退出是GH脉冲的主要原因。此外，最近克隆的生长激素释放肽(GHRP)的内源配体可能在生长激素脉冲的产生中起重要作用。在本研究中，我们将探讨绝经后妇女生长激素的分泌模式以及上述因素的可能作用。

Secretion of growth hormone (GH) is pulsatile. The mechanism by which GH pulses are caused is unkown. Possible explanations include pulsatile secretion of growth hormone-releasing hormone (GHRH), periodic declines of somatostatin (SRIH), a combination of both, or involvement of other central neuroendocrine regulatory molecules/factors. Our previous studies demonstrated that GHRH is required for pulsatile GH release. However it is possible that GHRH is simply permissive and that SRIH withdrawal is primarily responsible for GH pulses. In addition, and endogenous ligand to the recently cloned growth hormone releasing peptide (GHRP) might be important in the generation of GH pulses. In this study we will investigate the secretory pattern of GH in postmenopausal women and the possible role of the above mentioned factors.