title: Pimozide modulates the luteinizing hormone-releasing hormone effect on gonadotrophin release in the African catfish, Clarias lazera.
abstract: In the African catfish the effect of (i) the dopamine antagonist pimozide (PIM), (ii) a luteinizing hormone-releasing hormone analog (LH-RHa), and (iii) a combination of these substances on gonadotrophin (GTH) release and on ovulation was investigated. PIM alone increased plasma GTH levels in juvenile catfish but was ineffective in mature animals. LH-RHa increased plasma GTH levels in both juvenile and mature catfish and within 12 hr after the injection a high rate of ovulation (80%) was observed. PIM potentiated the LH-RHa effect on GTH release and ovulation. It was concluded that dopamine does not effect the GTH release directly, but modulates the effect of endogenous and exogenous gonadotrophin-releasing hormone.
mesh_terms: D000818:Animals; D004347:Drug Interactions; D005260:Female; D005399:Fishes / Q000097:blood*; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000494:pharmacology*; D006062:Gonadotropins / Q000097:blood*; D008297:Male; D010060:Ovulation / Q000187:drug effects; D010868:Pimozide / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D006062:Gonadotropins; D010868:Pimozide; D007987:Gonadotropin-Releasing Hormone; C010661:surfagon