IMMUNOLOCALIZATION OF TRANSFORMING GROWTH FACTOR-BETA(1) AND TRANSFORMING GROWTH FACTOR-BETA(2) IN THE MOUSE OVARY DURING GONADOTROPIN-INDUCED FOLLICULAR MATURATION

An immunohistochemical approach was utilized to evaluate the cellular distribution of transforming growth factor-beta(1) (TGF beta(1)) and t ransforming growth factor beta(2) (TGF beta(2)) at different stages of follicle development in the prepubertal mouse ovary under the followi ng conditions: (i) after pregnant mare's serum gonadotrophin (PMSG) tr eatment; (ii) after PMSG and human chorionic gonadotrophin (HCG) treat ment; (iii) after PMSG and HCG treatment plus mating, In the immature ovary, TGF beta(1) and TGF beta(2) immunoreactivities are localized in theca and granulosa cells and in oocytes, After PMSG treatment, TGF b eta(1) and TGF beta(2) immunoreactivities are localized in granulosa c ells; in addition, TGF beta(2) staining is noted in the matrix surroun ding antral cells. Staining for both TGF beta(1) and TGF beta(2) drops in the theca but persists in the oocyte. PMSG plus HCG treatment resu lts in a significant increase in TGF beta(1) and TGF beta(2) immunorea ctivity in the theca and in the maintenance of TGF beta(1) staining in both basal granulosa cells and cumulus cells whereas TGF beta(2) immu noreactivity is essentially localized in the matrix surrounding cumulu s cells. Staining for TGF beta(1) and TGF beta(2) persists in the oocy te. Following PMSG plus HCG treatment and mating, TGF beta(1) immunore activity is localized in the luteal cells of corpora lutea and TGF bet a(2) shows a similar localization pattern. This study provides evidenc e that TGF beta 1 and TGF beta 2 peptides are expressed in specific ce ll types during induced follicular maturation in the mouse ovary.