Rosskamp R
Universitäts-Kinderklinik, Bonn.
Klin Padiatr. 1988 Mar-Apr;200(2):81-8. doi: 10.1055/s-2008-1033691.
Growth hormone-releasing hormone was isolated 1982 from human pancreatic tumours. They were found to consist of three peptides (GHRH1-44, GHRH1-40, GHRH1-37) which in vivo and in vitro were specific stimulators of pituitary growth hormone secretion. These tumor-derived GHRHs were demonstrated to be identical to human hypothalamic GHRHs. Extrahypothalamic GHRH is present in some brain regions and in the gastrointestinal tract. Circulating GHRH is detectable in human plasma, but little is known about its function. Above all binding of GHRH to a specific receptor stimulates growth hormone secretion through formation of cyclic AMP. GHRH secretion is modulated by somatostatin, the somatomedins and growth hormone itself. Following single injection of GHRH1-44 i.v. the equilibration half-time is 1.0 +/- 0.2 min and elimination half-time is 6.8 +/- 1.2 min. Maximal growth hormone response is achieved after injection of 1 microgram/kg GHRH. Using higher GHRH-doses growth hormone can be stimulated via subcutaneous or intranasal application. A single i.v. GHRH-test is not sufficient to prove a pituitary defect since growth hormone can be stimulated following repetitive injections in some cases. About 50% of patients with growth hormone deficiency have a hypothalamic defect of GHRH release. In some of these patients GHRH s.c. can promote linear growth to the same degree as growth hormone treatment.
生长激素释放激素于1982年从人类胰腺肿瘤中分离出来。人们发现它们由三种肽组成（生长激素释放激素1 - 44、生长激素释放激素1 - 40、生长激素释放激素1 - 37），这些肽在体内和体外都是垂体生长激素分泌的特异性刺激物。这些肿瘤衍生的生长激素释放激素被证明与人类下丘脑生长激素释放激素相同。下丘脑外的生长激素释放激素存在于一些脑区和胃肠道中。在人类血浆中可检测到循环中的生长激素释放激素，但其功能却知之甚少。最重要的是，生长激素释放激素与特定受体结合可通过环磷酸腺苷的形成来刺激生长激素分泌。生长激素释放激素的分泌受到生长抑素、生长调节素和生长激素本身的调节。静脉注射生长激素释放激素1 - 44后，平衡半衰期为1.0±0.2分钟，消除半衰期为6.8±1.2分钟。注射1微克/千克生长激素释放激素后可达到最大生长激素反应。使用更高剂量的生长激素释放激素，可通过皮下或鼻内给药刺激生长激素分泌。单次静脉注射生长激素释放激素试验不足以证明垂体缺陷，因为在某些情况下，重复注射后生长激素仍可被刺激。约50%的生长激素缺乏患者存在下丘脑生长激素释放激素释放缺陷。在其中一些患者中，皮下注射生长激素释放激素可促进线性生长，其程度与生长激素治疗相同。
