Effect of hypothalamic infusion of a dopamine D1 receptor antagonist on prolactin secretion in the ewe.
In this study we investigated whether dopamine D1 receptors in the hypothalamus are involved in the control of prolactin secretion in ovariectomised, oestradiol implanted ewes. The D1 antagonist SCH23390 or vehicle was infused into either the preoptic area (POA) or the ventromedial hypothalamus (VMH). During infusion into the VMH, prolactin concentrations declined significantly and did not return to control values until more than 60 min after the infusions had stopped. In contrast, infusion into the POA had no significant effect. These results are in accord with the hypothesis that dopaminergic pathways within the hypothalamus stimulate prolactin secretion via dopamine D1 receptors in the VMH.
Curlewis
J D
JD
Department of Physiology and Pharmacology, University of Queensland, Brisbane, Australia.
Thiéry
J C
JC
Malpaux
B
B
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D005260:Female; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D007267:Injections; D011388:Prolactin / Q000378:metabolism*; D017447:Receptors, Dopamine D1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012756:Sheep
D001552:Benzazepines; D018492:Dopamine Antagonists; D017447:Receptors, Dopamine D1; D011388:Prolactin