Hypothermic, ACTH, and cortisol responses to ipsapirone in patients with mania and healthy controls

Background: The selective 5-HT1A receptor agonist ipsapirone causes dose-de pendent decrease in body temperature and increase in adrenocorticotropic ho rmone (ACTH) and coatisol release in humans. These responses are attenuated by 5-MT1A receptor antagonists, suggesting that hypothermia, ACTH and cort isol release induced by ipsapirone are indeed mediated by 5-MT1A receptors and that these responses provide a valid index of 5-MT1A receptor function in humans. Methods: To examine the 5-MT1A receptor sensitivity in patients with mania, we studied six manic patients and six age and sex matched healt hy controls. After obtaining a blood sample for baseline hormone levels and measuring body temperature, a single dose of 0.3 mg/kg of ipsapirone was g iven orally to all the subjects and further bloods and temperature reading were obtained every 30 minutes for 3 hours, Results: We found that ACTH and cortisol responses to ipsapirone were significantly increased in mania whe n compared to healthy controls, but there was no significant difference in hypothermic response to ipsapirone between the two groups. Limitations: A l ack of placebo control, heterogeneity of patients, and a small sample size are the limitations. Conclusions: Our findings suggest that manic patients may have enhanced postsynaptic 5-MT1A receptor sensitivity, but presynaptic 5-MT1A receptors are unaltered in this condition. Further placebo-controll ed studies with a larger number of manic patients are needed to verify this . (C) 1999 Elsevier Science B.V. All rights reserved.