PROSTAGLANDIN E(2)-9-KETOREDUCTASE AND PROSTAGLANDIN-F2-ALPHA ACTIVATE BRAIN AROMATASE TO INDUCE COURTSHIP IN THE MALE CRESTED NEWT, TRITURUS-CARNIFEX

Testosterone, 17 beta-estradiol, prostaglandin E(2) (PGE(2)), and pros taglandin F-2 alpha (PGF(2 alpha)) were monitored in plasma and in in vitro brain incubations during the main phases of male Triturus carnif ex courtship. Plasma and in vitro results were similar: testosterone w as highest in inactive males, while 17 beta-estradiol and PGF(2 alpha) were highest and PGE(2) lowest during approach. PGF(2 alpha) in vitro treatments decreased testosterone and increased 17 beta-estradiol, wh ile 9-ketoreductase inhibitor in vitro treatments increased testostero ne and decreased estradiol. In addition, in vitro aromatase and PGE(2) -9-ketoreductase activities were highest during approach. PGF(2 alpha) in vitro treatments increased aromatase, while 9-ketoreductase inhibi tor decreased aromatase. These results suggest that 9-ketoreductase an d PGF(2 alpha) enhance aromatase activity to trigger male Triturus car nifex courtship. (C) 1995 Academic Press, Inc.