Samaras S E, Hammond J M
Department of Medicine, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033, USA.
Am J Physiol. 1995 Jun;268(6 Pt 1):E1057-64. doi: 10.1152/ajpendo.1995.268.6.E1057.
Recombinant human insulin-like growth factor binding protein-3 (rhIGFBP-3) effects on basal, insulin-like growth factor I (IGF-I)-, and follicle-stimulating hormone (FSH)-stimulated progesterone (P4) secretion and [3H]aminoisobutyric acid (AIB) uptake by primary porcine granulosa cells (MDGs) and MDGs that have been passaged once (MDGp1) were assessed. Cells were treated concurrently or were preincubated with rhIGFBP-3 followed by treatment. rhIGFBP-3 had no effect on MDG or MDGp1 cell numbers after 24 h. Cotreatment with rhIGFBP-3 inhibited P4 secretion after treatment with FSH, IGF-I, and FSH plus IGF-I. FSH did not stimulate [3H]AIB uptake. However, the IGF-I-stimulated increase in [3H]AIB uptake was completely prevented by concurrent treatment with IGFBP-3. Preincubation of MDGp1 cells with IGFBP-3 dose dependently inhibited FSH- and IGF-I-stimulated P4 secretion. This inhibition was associated with increased cell association of the binding protein and increased IGF-I binding to the cells. These results indicate that IGFBP-3 is inhibitory to a variety of crucial functions in porcine granulosa cells, supporting a role for it in the regulation of granulosa cell function.
评估了重组人胰岛素样生长因子结合蛋白-3（rhIGFBP-3）对原代猪颗粒细胞（MDGs）和传代一次的MDGs（MDGp1）基础状态、胰岛素样生长因子I（IGF-I）及促卵泡激素（FSH）刺激的孕酮（P4）分泌和[3H]氨基异丁酸（AIB）摄取的影响。细胞同时接受处理，或先用rhIGFBP-3预孵育后再进行处理。24小时后，rhIGFBP-3对MDG或MDGp1细胞数量无影响。rhIGFBP-3与FSH、IGF-I以及FSH加IGF-I共同处理时，会抑制处理后的P4分泌。FSH不刺激[3H]AIB摄取。然而，IGFBP-3与IGF-I共同处理可完全阻止IGF-I刺激的[3H]AIB摄取增加。MDGp1细胞用IGFBP-3预孵育，可剂量依赖性地抑制FSH和IGF-I刺激的P4分泌。这种抑制与结合蛋白细胞结合增加以及IGF-I与细胞的结合增加有关。这些结果表明，IGFBP-3对猪颗粒细胞的多种关键功能具有抑制作用，支持其在颗粒细胞功能调节中的作用。
