Transforming growth factor-alpha in the adult bovine ovary: identification in growing ovarian follicles.
The pituitary gonadotropins and gonadal steroids are required for normal follicular growth and development but neither has been shown to act directly as a granulosa cell mitogen in vitro. A number of polypeptide growth factors, however, are known to have pronounced mitogenic effects on the cells of the follicle. We have localized transforming growth factor-alpha (TGF-alpha), a potent mitogen, in bovine thecal cells via immunoperoxidase staining using a monoclonal antibody for TGF-alpha that does not cross-react with epidermal growth factor. TGF-alpha staining is most intense in the theca of follicles at the discrete physiological stages known to show rapid granulosa cell growth (small follicles of 0.7-2.0 mm diameter). Staining intensity for TGF-alpha declines in large preovulatory follicles, coincident with the known decline in granulosa cell mitosis. These studies provide further evidence for paracrine interactions in the ovary and show that TGF-alpha may play an important role in the regulation of follicular development in the adult bovine ovary.
Lobb
D K
DK
Banting and Best Department of Medical Research, University of Toronto, Ontario, Canada.
Kobrin
M S
MS
Kudlow
J E
JE
Dorrington
J H
JH
D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D002417:Cattle; D002478:Cells, Cultured; D005260:Female; D006107:Granulosa Cells / Q000032:analysis; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D006080:Ovarian Follicle / Q000032:analysis* / Q000502:physiology; D010053:Ovary / Q000032:analysis*; D013799:Theca Cells / Q000032:analysis; D015291:Transforming Growth Factors / Q000032:analysis* / Q000502:physiology
D000911:Antibodies, Monoclonal; D015291:Transforming Growth Factors