The effects of reserpine and LHRH or salmon GnRH analogues on gonadotropin release, ovulation and spermiation in common carp (Cyprinus carpio L.).

The effects of reserpine (catecholamine depletor) and LHRH analogues on gonadotropin secretion, spermiation and ovulation of common carp were investigated. Injections of reserpine alone at a dose of 1 or 7 mg/kg of body weight stimulated spermiation, and reserpine at a dose of 1 mg/kg of body weight in combination with (D-Arg6, Trp7, Leu8, Pro9, NEt)-LHRH (s-GnRH-A) or with (D-Ala6, Pro9)-LHRH (LHRH-A) at a dose of 50 micrograms/kg of body weight caused an increase of plasma gonadotropin levels, spermiation and ovulation in 80-90% of the females. Simultaneous injection of reserpine and LHRH analogues was as effective as injection of reserpine followed by injection of LHRH analogues 6 h later.