Journal of Endocrinological Investigation

, Volume 12, Issue 2, pp 87–91 | Cite as

Effect of repeated doses of L-5-hydroxytryptophan and carbidopa on prolactin and aldosterone secretion in man

  • P. H. Vlasses
  • H. H. Rotmensch
  • B. N. Swanson
  • R. A. Clementi
  • R. K. Ferguson


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 < 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 (μg/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.


Serotonin prolactin aldosterone 


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Copyright information

© Italian Society of Endocrinology (SIE) 1989

Authors and Affiliations

  • P. H. Vlasses
    • 1
  • H. H. Rotmensch
    • 1
  • B. N. Swanson
    • 1
  • R. A. Clementi
    • 1
  • R. K. Ferguson
    • 1
  1. 1.Division of Clinical Pharmacology, Department of MedicineJefferson Medical College of Thomas Jefferson UniversityPhiladelphiaUSA

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