Androgenic regulation of plasma prostaglandin F levels in the rat.

Prostaglandins (PGs) can be synthesized by the testes (Ellis, 1972) and are present in the male accessory reproductive tissues and in the semen of various mammalian species (Bygdeman, Fredricsson, Svanborg & Samuelsson, 1970; Tan & Privett, 1972). Their physiological rôle in the male reproductive system is not understood but various effects of PG administration on the testes and male reproductive tract have been reported. These include decrease in plasma testosterone levels (Bartke, Musto, Caldwell &Behrman, 1973; Saksena, Safoury & Bartke, 1973), decrease in testicular blood flow (Free & Jaffe, 1972), and effects on contractions of the testis capsule (Seeley, Hargrove, Johnson & Ellis, 1972), on sperm transport (Hunt & Nicholson, 1972), and on contractile responses of the ductus deferens and seminal vesicles in vitro (Stahl, 1972; Taylor & Einhorn, 1972). In the human, certain cases of male infertility appear to be associated with a low seminal content of PGs (Bygdeman et al, 1970) and an increase in seminal PGs was recorded after administration of HCG or