Effect Of Laminin On The Human Chorionic Gonadotropin Stimulated Progesterone Production Of Granulosa Cells

Objective: To investigate the relative effects and mechanisms of laminin (LN) on the human chorionic gonadotropin( hCG )stimulated progesterone(P)production of rat preovulatory granulosa cells(GCs).Methods: GCs were obtained from preovulatory follicles in immature rats,and cultured in three groups:LN-coated group,uncoated group and LN-coated with anti-integrinα₆ mAb(GoH3) group. Attachment to the cultured plates was compared between the LN-coated group and uncoated group. GCs were cultured 48 hours in the presence of hCG with serum condition. The conditioned media was aspirated for measuring P content and LH/hCG receptor analysis was performed after cultured another 48 hours without serum.Results: Attachment of cells to cultured plates occurred significant earlier on LN,as compared with uncoated plates(6 h vs.16 h). Cells cultured on LN showed a marked elevation in progesterone production with or without the presence of hCG,and 5ug/mL GoH3 could restrain this stimulation effect remarkably. Another finding was that cells cultured on LN showed more number of LN/hCG receptors and higher hormone affinity to the receptor. LN can enhancing more progesterone production stimulated by hCG.Conclusion:The integrinα₆β₁-LN interaction is probably a local regulator of the ovary. LN may play an important role in granulosa cell luteinization during the periovulatory phase through interfering the function of LN/hCG receptors and enhancing the progesterone production of GCs.