FAILURE OF METOCLOPRAMIDE TO INFLUENCE LH, FSH AND TSH SECRETION OR THEIR RESPONSES TO RELEASING HORMONES

Abstract
I.v. metoclopramide (MET, 10 mg) induced a brisk PRL [prolactin] response with a mean .+-. SE peak of 85.3 .+-. 7.7 ng/ml maximal at 30 min [in humans]. L-Dopa, but not atropine pretreatment, attenuated the PRL response to MET. The antidopaminergic properties of MET mediate PRL secretion. MET did not influence basal levels of TSH [thyrotropin], LH [luteinizing hormone] or FSH [follicle stimulating hormone]. Neither did it affect their response to the respective releasing hormones. Dopaminergic blockade induced by i.v. MET, does not influence the secretion of the pituitary glycoprotein hormones.