Sortino M A, Aleppo G, Scapagnini U, Canonico P L
Institute of Pharmacology, University of Catania School of Medicine, Italy.
Gynecol Endocrinol. 1993 Jun;7(2):89-96. doi: 10.3109/09513599309152486.
Three different calcitonins: salmon calcitonin, eel calcitonin and the semi-synthetic analog [Asu1,7]eel calcitonin have been evaluated for their ability to affect phosphoinositide hydrolysis in primary cultures of anterior pituitary cells and in the osteoblast-like UMR-106 cells. In both cellular systems a repeated treatment with any form of calcitonin induced an inhibition of inositol phospholipid turnover. Eel calcitonin and its analog were always more potent than salmon calcitonin, but the efficacy of the three polypeptides was comparable. In cultured anterior pituitary cells, the inhibitory effect on phosphoinositide hydrolysis observed after chronic treatment with calcitonin was accompanied by a reduction of prolactin release. In contrast, a single treatment of cultured anterior pituitary cells with eel calcitonin or its analog [Asu1,7]eel calcitonin induced an increase of inositol phosphate accumulation, while salmon calcitonin was inactive. Accordingly, eel and [Asu1,7]eel calcitonin, but not salmon calcitonin, induced a slight but significant stimulation of prolactin secretion. In UMR-106 cells, the three calcitonins exhibited similar potency and efficacy in reducing parathyroid hormone-stimulated 4 beta[3H]-phorbol-12,13-dibutyrate ([3H]PdBu) binding, an indirect index of protein kinase C activation. Taken together, these results suggest that, either at the pituitary or in osteoblast-like cells, some of the effects exerted by calcitonin may be ascribed to an interference with the intracellular events initiated by modulation of phosphoinositide turnover.
鲑鱼降钙素、鳗鱼降钙素和半合成类似物[Asu1,7]鳗鱼降钙素，评估它们影响垂体前叶细胞原代培养物和类成骨细胞UMR-106细胞中磷酸肌醇水解的能力。在这两种细胞系统中，用任何形式的降钙素重复处理均诱导肌醇磷脂周转受到抑制。鳗鱼降钙素及其类似物总是比鲑鱼降钙素更有效，但这三种多肽的功效相当。在培养的垂体前叶细胞中，降钙素长期处理后观察到的对磷酸肌醇水解的抑制作用伴随着催乳素释放的减少。相反，用鳗鱼降钙素或其类似物[Asu1,7]鳗鱼降钙素单次处理培养的垂体前叶细胞会诱导肌醇磷酸积累增加，而鲑鱼降钙素则无活性。因此，鳗鱼降钙素和[Asu1,7]鳗鱼降钙素，但不是鲑鱼降钙素，诱导催乳素分泌有轻微但显著的刺激作用。在UMR-106细胞中，三种降钙素在降低甲状旁腺激素刺激的4β-[3H]-佛波醇-12,13-二丁酸酯（[3H]PdBu）结合方面表现出相似的效力和功效，这是蛋白激酶C活化的间接指标。综上所述，这些结果表明，无论是在垂体还是在类成骨细胞中，降钙素发挥的某些作用可能归因于对由磷酸肌醇周转调节引发的细胞内事件的干扰。
