Effects of monoaminergic and cholinergic drugs on release of follicle stimulating hormone from co-incubated pituitary glands and hypothalami.

1. Male rat pituitary glands and hypothalami were incubated with agonists and antagonists of various neurotransmitters, and release of follicle stimulating hormone (FSH) measured. 2. Noradrenaline and cholinergic agonists stimulated release of FSH, responses blocked by the alpha antagonist, phentolamine, and by atropine respectively. 3. Dopamine did not affect basal, but inhibited noradrenaline-stimulated, release of FSH. The dopamine antagonist, pimozide, stimulated release of FSH. 4. Neither serotonin nor its antagonist, methysergide, affected release of FSH. 5. None of these drugs acted directly on the pituitary gland, suggesting that they act by altering secretion of the gonadotrophin releasing hormone.