In vivo effects of oLH and LHRH-analog on sex reversal and plasma sex steroid profiles in the female monopterus albus

Abstract

The effects of ovine-luteinizing hormone (oLH) or a synthetic analog of luteinizing hormone-releasing hormone. Des-Gly 10(S-Ala 6)-LHRH ethylamide acetate salt-(LHRH-A), on the female phase of the protogynous Monopterus albus were investigated, and the plasma levels of androstenedione (Ad), testosterone (T), 11-oxotestosterone (KT), 11β-hydroxytestosterone (OHT), 17β-estradiol (E2) and progesterone were determined. In the post-spawning stage, oLH induced precocious sex reversal in the gonad from female to male and increased plasma levels of Ad, T, KT and OHT. However, such oLH effects in M. albus females were slight at the early prespawning stage, and no significant signs of precocious sex reversal were found either in gonadal structure or in plasma hormones as those in postspawning treatment. After LHRH-A treatment of M. albus females in both postspawning and early prespawning stages, the gonadal structure remained 'female type' with no sign of proliferation of either Leydig cells or male germ cells. The plasma levels of E2 were greatly increased after the treatment.