Title: Intraovarian release of eggs in the rat after indomethacin treatment at pro-oestrus
Abstract: Department of Anatomy, Medical Faculty, Erasmus University, Rotterdam, The Netherlands Indomethacin has been shown to block ovulation in rats (Armstrong & Grinwich, 1972; Tsafriri, Lindner, Zor & Lamprecht, 1972a; Orczyk & Behrman, 1972) and other mammals (O'Grady, Caldwell, Auletta & Speroff, 1972; Grinwich, Kennedy & Armstrong, 1972; Saksena, Lau & Shaikh, 1974). The release of LH is not affected in indomethacin-treated rats (Tsafriri et al., 1972b), and it has been suggested that indomethacin exerts its ovulation-inhibiting action at the ovary (Grinwich et al., 1972; Tsafriri et al., 1972a; Saksena et al., 1974). It is not clear, however, how indomethacin affects the mechanism of ovulation, and in the present study the ovaries of rats treated with indomethacin at pro-oestrus were examined histologically. Adult female rats of the Wistar substrain R'Amsterdam and weighing 180-200 g were used after two consecutive 5-day cycles. Indomethacin (Indocid capsules: Merck, Sharp & Dohme) was suspended in