Inhibition of thyrotropin and prolactin secretion by dopamine in man.
The effect of dopamine on thyrotropin (TSH) and prolactin (PRL) levels was studied in 5 normal subjects, 7 women with galactorrhea, 9 acromegalics and 4 patients with primary hypothyroidism. Dopamine infused at the rate of 280 micrograms/min produced significant decrease in plasma TSH and PRL levels in all four groups, though a lower fall in TSH was noted in acromegalics. A similar reduction in PRL was also noted after 28 micrograms/min dopamine. Phentolamine infusion (0.5 mg/min) had no effect on PRL response to dopamine. These results indicate that a dopaminergic stimulation led to an inhibition of TSH and PRL secretion. Since the high polarity of dopamine impedes its passage through the blood-brain barrier, its site of action should be outside this barrier, probably in the pituitary.
D000172:Acromegaly / Q000503:physiopathology; D000328:Adult; D000368:Aged; D004298:Dopamine / Q000494:pharmacology*; D004700:Endocrine System Diseases / Q000503:physiopathology*; D005260:Female; D005687:Galactorrhea / Q000503:physiopathology; D006801:Humans; D007037:Hypothyroidism / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010646:Phentolamine / Q000494:pharmacology; D011247:Pregnancy; D011388:Prolactin / Q000097:blood* / Q000378:metabolism; D013972:Thyrotropin / Q000097:blood* / Q000378:metabolism
D011388:Prolactin; D013972:Thyrotropin; D004298:Dopamine; D010646:Phentolamine