Oxytocin interference in the effects induced by inhalation of 7.5% CO₂ in healthy volunteers.

Oliveira, Danielle Chaves Gomes; Chagas, Marcos Hortes N.; Garcia, Luis Vicente; Crippa, José Alexandre S.; Zuardi, Antonio W

Objective The objective of this study was to assess the acute effect of intranasally administered oxytocin (OT) on subjective states, cardiovascular, and endocrine parameters in healthy volunteers who inhaled 7.5% CO2. Methods Forty-five subjects were allocated into three matched groups of subjects who received 24 international units (IU) of OT, 2 mg of lorazepam (LZP), or placebo (PL). The challenge consisted of medical air inhalation for 20 min, 10 min of rest, and CO2 7.5% inhalation for 20 min. Subjective effects were evaluated by self-assessment scales; heart rate, blood pressure, skin conductance, and salivary cortisol were also measured. Assessments were performed at four time points: (i) baseline (−15 min); (ii) post-air inhalation (90 min); (iii) post-CO2 inhalation (120 min), and (iv) post-test (160 min). Results CO2 inhalation significantly increased the anxiety score in the PL group compared with the post-air measurement but not in the OT or LZP groups. The LZP reduced anxiety after medical air inhalation. Other parameters evaluated were not affected by OT. Conclusion OT, as well as LZP, prevented CO2-induced anxiety, suggesting that this hormone has anxiolytic properties. Copyright © 2012 John Wiley & Sons, Ltd.

OXYTOCIN; OLIGOPEPTIDES; PITUITARY hormones; CARBON dioxide; ANXIETY disorders

Human Psychopharmacology: Clinical & Experimental, 2012, Vol 27, Issue 4, p378

0885-6222

Academic Journal

10.1002/hup.2237