LH-releasing hormone (LH-RH)によるアユの排卵促進について

This study was carried out to discern the effects of peptide hormone LH-RH on ovulation in the ayu, Plecoglossus altivelis. Total ovary weight and GSI were significantly greater in the fish treated with LH-RH than in the control. Ovulation was clearly observed in the fish treated with 200μg LH-RH within 2 days after a single injection. In the ventral portion of the proximal pars distalis of the pituitary the content of the basophil (gonadotroph) mostly disappeared for the 2 day period. Furthermore, in the LH-RH-treated fish body weight increased by several percent. Water and sodium content were also greater than in the control. This LH-RH, by causing the release of endogenous gonadotropin, induces the same sequence of ovarian events as does the treatment of exogenous gonadotropin.