|Budget Amount *help
¥6,700,000 (Direct Cost : ¥6,700,000)
Fiscal Year 1994 : ¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1993 : ¥4,700,000 (Direct Cost : ¥4,700,000)
Recently, sex steroid hormones, growth factors, and cytokines, which modulate the effects of gonadotropins, have been proposed to be involved in the local regulation for ovarian function. In this study, we investigated the regulatory factors including endocrine and immune ones to totally understand local regulation systems for ovarian cell differentiation. In the aim, we used porcine granulosa cell culture and human luteinizing granulosa cell culture, and have established an immature mouse model for ovulation induction, porcine and human theca cell culture. By using porcine granulosa cell culture, aminopeptidase activity, which can metabolize several peptides including cytokines, was revealed to be present one the cell surface of granulosa cells. The inhibition of the aminopeptidase activity by an inhibitor, bestatin, enhanced luteinization of granulosa cells. Local administration of bestatin into murine ovaries stimulated ovulation, indicating that membrane-bound peptidase (s) are important regulators for follicular growth. Another membrane-bound pepitdase, dipeptidyl peptidase IV (DPPIV) , was found to be expressed on human luteinizing granulosa cells during corpus luteum formation. Flow cytometric analysis using human luteinizing granulosa cell culture indicated that the expression of DPPIV is enhanced by interleukin-1alpha and tumor necrosis factor-alpha, but not by hCG.HLA-DR and LFA-3, which are cell adhesion-related cell surface antigens for CD2 and 4 molecules expressed on T-lymphocytes, were also revealed to be expressed on human luteinizing granulosa cells, being compatible with the previously reported observation that peripheral lymphocytes enhanced progesterone production by human luteinizing granulosa cells. Flow cytometry showed that the expression of these antigens were also regulated by cytokines, suggesting that an immune system as well as an endocrine system operates during corpus luteum formation.