Supersensitivity of anterior pituitary dopamine receptors involved in the inhibition of prolactin secretion following destruction of the medial basal hypothalamus.
The medial basal hypothalamus of ovariectomized rats was destroyed using a modified Halász knife. Large increases in prolactin secretion were observed 1 and 14 days following the lesions. Long- and short-term lesioned animals were anesthetized with chloral hydrate and treated with various doses of apomorphine (0.05, 0.2, 2, 5 mg/kg). Blood samples were obtained before and 10, 30 and 60 minutes after the injection. Both the 0.05 and 0.2 mg/kg doses caused significantly greater and longer-lasting inhibition of prolactin in long-term than in short-term lesioned animals. Since the MBH was totally destroyed this study suggests that anterior pituitary dopamine receptors involved in the inhibition of prolactin secretion become supersensitive in long-term lesioned rats.
D000818:Animals; D001058:Apomorphine / Q000494:pharmacology; D002369:Castration; D004298:Dopamine / Q000378:metabolism*; D005260:Female; D007031:Hypothalamus / Q000502:physiology*; D007033:Hypothalamus, Middle / Q000502:physiology*; D010902:Pituitary Gland / Q000378:metabolism*; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D011388:Prolactin / Q000097:blood / Q000378:metabolism*; D051381:Rats; D011941:Receptors, Adrenergic
D011941:Receptors, Adrenergic; D011388:Prolactin; D001058:Apomorphine; D004298:Dopamine