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 transforming growth factor beta(2) (TGF beta(2)) at different stages of follicle development in the prepubertal mouse ovary under the following conditions: (i) after pregnant mare's serum gonadotrophin (PMSG) treatment; (ii) after PMSG and human chorionic gonadotrophin (HCG) treatment; (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 beta(1) and TGF beta(2) immunoreactivities are localized in granulosa cells; in addition, TGF beta(2) staining is noted in the matrix surrounding 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 results in a significant increase in TGF beta(1) and TGF beta(2) immunoreactivity in the theca and in the maintenance of TGF beta(1) staining in both basal granulosa cells and cumulus cells whereas TGF beta(2) immunoreactivity is essentially localized in the matrix surrounding cumulus cells. Staining for TGF beta(1) and TGF beta(2) persists in the oocyte. Following PMSG plus HCG treatment and mating, TGF beta(1) immunoreactivity is localized in the luteal cells of corpora lutea and TGF beta(2) shows a similar localization pattern. This study provides evidence that TGF beta 1 and TGF beta 2 peptides are expressed in specific cell types during induced follicular maturation in the mouse ovary.