Ceda G P, Denti L, Ceresini G, Rastelli G, Dotti C, Cavalieri S, Valenti G, Hoffman A R
Department of Gerontology and Geriatrics, University of Parma, G. Studard Hospital, Italy.
Acta Endocrinol (Copenh). 1989 Apr;120(4):416-22. doi: 10.1530/acta.0.1200416.
Calcitonin has been shown to modulate pituitary hormone secretion in a variety of ways. In this study we examined the effects of a salmon calcitonin infusion on GHRH-induced GH secretion in 5 normal men. In addition, in vitro experiments were performed using primary cultures of rat anterior pituitary cells in order to examine whether there is a direct pituitary effect of CT. Infusion of CT significantly blunted the GH response to GHRH in all subjects without affecting basal GH secretion or plasma calcium levels. Infusion of CT was accompanied by significant increases in ACTH, beta-endorphin, cortisol and free fatty acid levels, and by a significant decrease in serum insulin levels. The addition of CT to primary cultures of rat pituitary cells did not alter basal or stimulated secretion of GH or ACTH. These results indicate that: 1) CT blunts the GH response to GHRH; 2) CT infusion results in the stimulation of the hypothalamic-pituitary-adrenal axis, and 3) this effect is probably exerted at the hypothalamic level, since no direct activity of CT was documented in vitro on either GH or ACTH secretion.
降钙素已被证明能以多种方式调节垂体激素分泌。在本研究中，我们检测了鲑鱼降钙素输注对5名正常男性生长激素释放激素（GHRH）诱导的生长激素（GH）分泌的影响。此外，为了检测降钙素（CT）是否对垂体有直接作用，我们使用大鼠垂体前叶细胞原代培养进行了体外实验。输注CT显著减弱了所有受试者对GHRH的GH反应，而不影响基础GH分泌或血浆钙水平。输注CT伴随着促肾上腺皮质激素（ACTH）、β-内啡肽、皮质醇和游离脂肪酸水平的显著升高，以及血清胰岛素水平的显著降低。将CT添加到大鼠垂体细胞原代培养物中，并未改变GH或ACTH的基础分泌或刺激分泌。这些结果表明：1）CT减弱了对GHRH的GH反应；2）CT输注导致下丘脑-垂体-肾上腺轴的激活；3）这种作用可能是在下丘脑水平发挥的，因为在体外未记录到CT对GH或ACTH分泌有直接作用。
