Shah G V, Epand R M, Orlowski R C
Department of Biochemistry, McMaster University, Hamilton, Ontario, Canada.
J Endocrinol. 1988 Feb;116(2):279-86. doi: 10.1677/joe.0.1160279.
Salmon calcitonin inhibited TRH-stimulated release of prolactin in isolated pituitary cells from untreated female rats. These cells were still capable of responding to the fresh addition of TRH after the removal of calcitonin. Calcitonin gene-related peptide had only a weak effect in inhibiting prolactin release in these cells. Pituitary cells isolated from female rats which had been treated with weekly s.c. injections of 1 mg oestradiol dipropionate for 4 weeks, exhibited a marked increase in the magnitude of the inhibition of prolactin release by salmon calcitonin. Both basal and TRH-stimulated release of prolactin were inhibited by concentrations of 0.1 nmol salmon calcitonin/l or higher. Prolactin release from these cells was also inhibited at somewhat higher concentrations by calcitonin gene-related peptide. Our results demonstrate that calcitonin can directly inhibit basal as well as TRH-stimulated prolactin release by acting directly at the pituitary. The results strongly suggest that the peptide may be involved in the regulation of prolactin release in certain physiological conditions.
鲑鱼降钙素可抑制未处理的雌性大鼠分离垂体细胞中促甲状腺激素释放激素（TRH）刺激的催乳素释放。去除降钙素后，这些细胞仍能对新添加的TRH产生反应。降钙素基因相关肽对抑制这些细胞中催乳素释放的作用较弱。从每周皮下注射1mg二丙酸雌二醇共4周的雌性大鼠分离出的垂体细胞，鲑鱼降钙素对催乳素释放的抑制作用显著增强。0.1nmol/l或更高浓度的鲑鱼降钙素可抑制催乳素的基础释放和TRH刺激的释放。降钙素基因相关肽在稍高浓度时也可抑制这些细胞的催乳素释放。我们的结果表明，降钙素可通过直接作用于垂体，直接抑制催乳素的基础释放以及TRH刺激的释放。结果强烈提示，该肽可能在某些生理条件下参与催乳素释放的调节。
