Effect of repeated doses of L-5-hydroxytryptophan and carbidopa on prolactin and aldosterone secretion in man.
To evaluate changes in serum prolactin and plasma and urine aldosterone after a serotonergic challenge, 8 healthy men (19 to 42 yr), taking dexamethasone (0.75 mg qid), received the serotonin precursor L-5-hydroxytryptophan (L5HTP; 100 mg qid) with the peripheral decarboxylase inhibitor carbidopa (C; 50 mq qid) or matching placebos in a randomized, crossover manner. Serum prolactin concentration increased in all subjects after L5HTP/C in comparison to placebo, mean (SD) prolactin (ng/ml) at 8 h after dosing was 19.8 +/- 6.3 after L5HTP/C and 12.0 +/- 3.1 after placebo (p less than 0.05). In contrast, in comparison to values on placebo, L5HTP/C had no apparent effect on mean plasma concentration at all observation times; mean (SD) aldosterone (ng/dl) at 8 h after dosing was 12.0 +/- 5.1 and 12.0 +/- 3.8 after placebo (NS). Mean (SD) urinary aldosterone (micrograms/24 h), Na+(mEq/24 h) and K+(mEq/24 h) excretion were 7.0 +/- 4.4, 49.3 +/- 30.6, 30.1 +/- 11.2, after L5HTP/C and 7.4 +/- 5.8, 59.7 +/- 23.9, 33.3 +/- 7.4 after placebo (NS). Under these study conditions, subacute serotonergic stimulation with oral L5HTP/C resulted in prolactin but not aldosterone release.
Vlasses
P H
PH
Department of Medicine, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA 19107.
Rotmensch
H H
HH
Swanson
B N
BN
Clementi
R A
RA
Ferguson
R K
RK
D006916:5-Hydroxytryptophan / Q000008:administration & dosage* / Q000494:pharmacology; D000328:Adult; D000450:Aldosterone / Q000378:metabolism*; D002230:Carbidopa / Q000008:administration & dosage* / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D009318:Natriuresis / Q000187:drug effects; D011388:Prolactin / Q000378:metabolism*
D000450:Aldosterone; D006897:Hydroxyindoleacetic Acid; D003907:Dexamethasone; D011388:Prolactin; D006916:5-Hydroxytryptophan; D002230:Carbidopa