Bhaumick B, Dawson E P, Bala R M
Biochem Biophys Res Commun. 1987 Apr 29;144(2):674-82. doi: 10.1016/s0006-291x(87)80018-9.
The effects of insulin-like growth factor (IGF)-I and insulin on placental lactogen production (hPL) by term human placental explants were studied. The hPL content in medium and explant decreased rapidly after first 24 hours of culture. The decrease thereafter was gradual and reached a plateau by day 4 of culture. The decrease of HPL content in placental culture has previously been suggested being due to the depletion of a rapidly secreting preformed pool of hPL. Addition of IGF-I (0.1-10 micrograms/ml) and insulin (1-20 micrograms/ml) stimulated the decreased level of hPL in tissue and medium after 24 hours in culture. IGF-I was 10 times more potent than insulin in stimulating hPL. These findings suggest that IGF-I and insulin effects the production of hPL by placenta. The lower potency of insulin may indicate that the effect of insulin on hPL production is via IGF-I receptor.
研究了胰岛素样生长因子（IGF）-I和胰岛素对足月人胎盘外植体产生胎盘催乳素（hPL）的影响。培养的前24小时后，培养基和外植体中的hPL含量迅速下降。此后下降逐渐缓慢，到培养第4天达到平台期。胎盘培养中HPL含量的下降此前曾被认为是由于快速分泌的预先形成的hPL池耗尽所致。添加IGF-I（0.1 - 10微克/毫升）和胰岛素（1 - 20微克/毫升）可刺激培养24小时后组织和培养基中hPL下降的水平。IGF-I刺激hPL的效力比胰岛素高10倍。这些发现表明IGF-I和胰岛素影响胎盘hPL的产生。胰岛素效力较低可能表明胰岛素对hPL产生的作用是通过IGF-I受体介导的。
