Characterization of cytoskeletal proteins in follicular structures of cows with cystic ovarian disease.

The distribution of intermediate filaments (vimentin, cytokeratins, desmin) and microfilaments (alpha-smooth muscle actin and muscle specific actin) was studied immunohistochemically in bovine ovaries, with and without cystic ovarian disease. The immunohistochemically stained area (IHCSA), was quantified by image analysis, to evaluate the expression of these cytoskeletal proteins in the follicular wall of healthy antral, atretic, and cystic follicles. The granulosa cell layer of cystic follicles and atretic follicles had a significantly larger IHCSA for vimentin than did healthy antral follicles. Cytokeratins reacted lightly in the granulosa cells of antral follicles of normal ovaries, whereas granulosa cells of atretic and cystic follicles showed significantly higher IHCSA values. Immunohistochemical localization of desmin, muscle specific actin, and alpha-smooth muscle actin was restricted to the theca externa. This study supports earlier suggestions that strongly positive reactions with vimentin and cytokeratin antibodies observed in the granulosa cells of cystic follicles are due to the reorganization that occurs in the follicle during the process of cystic development, and are associated with changes in the expression of cytoskeletal proteins that are essential to proper cellular functioning.

Intraovarian localization of growth factors in induced cystic ovaries in rats.

We hypothesized that the special hormonal environment present in animals with cystic ovarian disease (COD) interferes with cellular production of growth factors (GFs). The objective of the present study was to characterize the expression of insulin-like growth factor (IGF)-I, fibroblast growth factor (FGF)-2 and vascular endothelial growth factor (VEGF) in induced COD using immunohistochemistry. We used an experimental model based on the exposure to constant light of adult rats during 15 weeks. We quantified the expression of GFs in cystic and normal ovaries by the Immunohistochemical Stained Area (IHCSA). In animals with COD, a significant reduction in the IHCSA of IGF-I in the follicular fluid, theca and granulosa layers of cysts occurred; and an increase in the interstitial tissue with regard to the control group. We found moderate immunoreactivity of FGF-2 in granulosa and theca layers of secondary and tertiary follicles and lower expression in the granulosa and theca interna layers of cystic follicles. Immunoexpression of VEGF was found in granulosa and theca cells of secondary and tertiary follicles. This study shows changes in the ovarian expression of IGF-I, FGF-2 and VEGF in induced COD. We can propose that an alteration in the control of the follicular dynamic, through the GFs, added to other features, could be involved in the ovarian cyst pathogenesis.