Patel N, Alsat E, Igout A, Baron F, Hennen G, Porquet D, Evain-Brion D
INSERM U 427, Ecole Normale Supérieure, Paris, France.
J Clin Endocrinol Metab. 1995 May;80(5):1743-6. doi: 10.1210/jcem.80.5.7745029.
Human placenta specifically expresses the GH-V gene leading to the production of placental Growth Hormone (PGH). During pregnancy, PGH levels increase progressively in maternal blood, but its regulation remains unknown. In this study the effect of glucose on PGH secretion by human term placenta was tested, in vitro, by means of two different experimental models: organ culture of villous tissue and primary culture of isolated cytotrophoblasts. PGH was assayed in the culture medium by an immunoradiometric assay using a specific PGH monoclonal antibody. The presence of glucose (25 mmol/L) in the culture medium significantly inhibited (p < 0.001) the secretion of PGH by either placental villous explants or by cultured trophoblast cells. This inhibitory effect of glucose on PGH secretion was dose-dependent. More than 50% inhibition being observed with 5.5 mmol/L. In the same conditions, the daily production of hPL and hCG, were unmodified. Furthermore, the glucose-induced inhibition of PGH secretion was more effective when cultured trophoblast cells are differentiated into syncytiotrophoblast. This study demonstrates, for the first time, that among the gestational polypeptide hormones secreted by the human placenta, only PGH secretion is modulated by glucose, suggesting a key metabolic role for this hormone during pregnancy.
人类胎盘特异性表达生长激素变体（GH-V）基因，从而产生胎盘生长激素（PGH）。在怀孕期间，母体血液中PGH水平逐渐升高，但其调节机制尚不清楚。在本研究中，通过两种不同的实验模型，即绒毛组织器官培养和分离的细胞滋养层细胞原代培养，在体外测试了葡萄糖对足月人胎盘PGH分泌的影响。使用特异性PGH单克隆抗体通过免疫放射测定法测定培养基中的PGH。培养基中葡萄糖（25 mmol/L）的存在显著抑制（p < 0.001）胎盘绒毛外植体或培养的滋养层细胞分泌PGH。葡萄糖对PGH分泌的这种抑制作用是剂量依赖性的。在5.5 mmol/L时观察到超过50%的抑制作用。在相同条件下，人胎盘催乳素（hPL）和人绒毛膜促性腺激素（hCG）的每日产量未改变。此外，当培养的滋养层细胞分化为合体滋养层时，葡萄糖诱导的PGH分泌抑制作用更有效。本研究首次证明，在人胎盘分泌的妊娠多肽激素中，只有PGH分泌受葡萄糖调节，这表明该激素在怀孕期间具有关键的代谢作用。
