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

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 microgram/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 158 +/- 29 mg (p