Pindolol pretreatment blocks stimulation by meta-chlorophenylpiperazine of prolactin but not cortisol secretion in normal men

Herbert Y. Meltzer*, Michael Maes

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

56 Scopus citations


Previous reports from this laboratory have shown that pindolol, a partial serotonin1A receptor agonist, inhibited prolactin, but not cortisol secretion induced by administration of the serotonin (5-HT) precursor l-5-hydroxytryptophan or the direct-acting 5-HT2A 5HT2C receptor agonist MK-212. The findings suggest additive or interactive effects of 5-HT1A and 5-HT2A 5-HT2C receptors in modulating 5-HT-related prolactin, but not cortisol, responsivity. To examine further the role of 5-HT1A and 5-HT2A 5-HT2C receptors in prolactin and cortisol secretion in healthy men, the effects of meta-chlorophenylpiperazine (mCPP), a potent 5-HT receptor agonist, on the above hormones were studied in eight healthy men with and without pindolol pretreatment. It has previously been demonstrated that ketanserin, a 5-HT2A antagonist, and ritanserin, a 5-HT2A 5-HT2C antagonist, block the prolactin and attenuate the hypothalamic-pituitary-adrenal axis responses to mCPP in man or rodents. Administration of mCPP induced a significant increase in plasma concentrations of prolactin and cortisol. The mCPP-induced prolactin concentrations were significantly blocked by pretreatment with pindolol, whereas mCPP-stimulated cortisol levels were not diminished by pindolol pretreatment. Thus, mCPP-induced prolactin secretion appears to require the availability of both 5-HT2C and 5-HT1A receptor activation, since blockade of either of these receptors may diminish the mCPP-induced prolactin response. Cortisol secretion stimulated by mCPP may occur following 5-HT2C receptor stimulation in the presence of 5-HT1A receptor blockade.

Original languageEnglish (US)
Pages (from-to)89-98
Number of pages10
JournalPsychiatry Research
Issue number2
StatePublished - Sep 29 1995


  • Hormones
  • Hypothalamic-pituitary-adrenal axis
  • Serotonin receptor subtypes

ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Biological Psychiatry


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