The influence of psychotropic drugs and releasing hormones on anterior pituitary hormone secretion in healthy subjects and depressed patients

Abstract

Pharmacoendocrinological studies have shown that psychotropic drugs with different actions have different effects on anterior pituitary hormone secretion in man. Substances with different effects on the central nervous system are characterized by a different pharmacoendocrinological profile. Studies with various receptor blockers have shown varying influences on the DMI-induced growth hormone, prolactin, and ACTH/cortisol secretion. Growth hormone stimulation was shown to be mediated by alpha 2-receptors and inhibited by beta-receptors. Investigations in male and female endogenous depressive patients demonstrated a significantly blunted growth hormone response to DMI compared with age- and sex-matched healthy subjects. A comparative study in male endogenous depressive patients showed a significantly diminished growth hormone stimulation both after DMI and after growth hormone-releasing hormone compared to healthy male subjects. In further tests a simultaneous application of four releasing hormones (GHRH, CRH, GnRH, TRH) was used. These investigations showed a significantly lower GH stimulation in endogenous depressive patients compared with age- and sex-matched healthy subjects, but not in neurotic depressive or schizophrenic patients. Cortisol stimulation was similar in all groups of patients and healthy subjects. TSH stimulation was significantly lower in endogenous depressive and schizophrenic patients than in healthy subjects. Somatomedin-C concentrations were significantly elevated in endogenous depressed patients compared with healthy subjects. The blunted growth hormone response in endogenous depression could be explained by inhibitory influences such as increased somatomedin-C concentrations or a hyperactivity of central beta-adrenergic-receptors.