Induced final maturation and ovulation in a small anabantoid teleost, the dwarf gourami (Colisa lalia). II. The modulatory effects of monoaminergic and opioid drugs on the responsiveness to LHRHa

Abstract

There was evidence that the proportion of dwarf gourami, Colisa lalia (Hamilton), ovulating in response to the injection of an emulsion of LHRHa in Freund's incomplete adjuvant could be increased by concurrent treatment with dopamine antagonists, suggesting an inhibitory dopaminergic D2 control of gonadotrophin secretion. There was also evidence that α- and β-adrenergic agonists may enhance the ovulatory response to LHRHa; on the other hand, α- and β-adrenergic antagonists were without effect at the dosages tested. There was also some inconsistent evidence for an inhibitory action of opioidergic systems