Systemic treatment in the rat with epidermal growth factor causes polycystic growth of the ovaries

Abstract

Background: It has previously been suggested that epidermal growth factor (EGF) plays a role in the function of the ovary. We administered systemic EGF to assess the influence of EGF receptor stimulation on the morphology of the ovaries. Methods: Forty-eight female Wistar rats were allocated to five groups receiving EGF treatment (150 pg/kg/day) for 0 (controls), 1, 2, 3 and 4 weeks. All rats were exactly 8 weeks at the start of the experiment and 12 weeks at sacrifice. The EGF was administered in the weeks prior to sacrifice. At sacrifice, the perfusion-fixed ovaries were removed and weighed, and the volumes of tissue components were quantified using stereology. Results: EGF administration increased the total weight of the ovaries from 129+-18 mg in the controls to 158k29 mg (p<0.05) after one week. In subsequent weeks the total weight increased to 230273 mg (p<O.OOl). The weight gain after one week of treatment was exclusively due to a fourfold increase in follicular cyst volume (p<O.Ol). In subsequent weeks the cyst volume was increased up to eightfold. After 2, 3 and 4 weeks of treatment the quantity of luteinizing cells was likewise increased by 70% (p<O.Ol). Conclusion: EGF administration causes the follicular cells to produce cysts and increases the quantity of luteinizing cells.

Epidermal growth factor regulation of connexin 43 in cultured granulosa cells from preantral rabbit follicles

“…Human preantral follicles responded in vitro to exogenous EGF with increased growth and a corresponding increase in transforming growth factor-b (TGF-b) receptor II expression in granulosa cells (Roy and Kole, 1998). Systemic administration of EGF to mature female rats caused ovarian growth due to an increased volume of fluid in follicular cysts and an increase in the number of luteinizing cells (Christiansen et al, 1996). In porcine granulosa cells from primary and secondary follicles, EGF stimulates granulosa cell proliferation (Morbeck et al, 1993).…”