Intranasal oxytocin attenuates cortisol levels during social stress inductions.
However, no research to date has documented the dose–response relation between intranasal oxytocin administration and cortisol, and researchers examining intranasal oxytocin have not examined the cortisol response to physical stress.
We therefore examined the effects of 24IU and 48IU of intranasal oxytocin on the cortisol response to vigorous exercise.
Seventeen males participated in a randomized, placebo-controlled, double-blind, and within-subject experiment.
Participants engaged in vigorous exercise for 60 min following the administration of placebo or intranasal oxytocin on three occasions.
Saliva samples and mood ratings were collected at eight intervals across each session.
Salivary cortisol concentrations changed over time, peaking after 60 min of exercise (quadratic: F(1,16) = 7.349, p = .015, partial η2 = .32).
The 24IU dose of oxytocin attenuated cortisol levels relative to placebo (F(1,16) = 4.496, p = .05, partial η2 = .22) and the 48IU dose, although the latter fell just short of statistical significance (F(1,16) = 3.054, p = .10, partial η2 = .16).
There was no difference in the cortisol response to exercise in participants who were administered 48IU of intranasal oxytocin relative to placebo.
Intranasal oxytocin had no effect on mood.
This is the first study to demonstrate that the effect of intranasal oxytocin on salivary cortisol is dose-dependent, and that intranasal oxytocin attenuates cortisol levels in response to physical stress.
Future research using exogenous oxytocin will need to consider the possibility of dose–response relations.
- Intranasal oxytocin;
- a Centre for Research in Human Development, Department of Psychology, Concordia University, Montréal, QC, Canada
- b Department of Exercise Science, Concordia University, Montréal, QC, Canada
- c Research Center, Hôpital du Sacré-Cœur de Montréal—A University of Montréal Affiliated Hospital, Montréal, QC, Canada
- d Research Center, Montréal Heart Institute—A University of Montréal Affiliated Hospital, Montréal, QC, Canada
- e Douglas Mental Health University Institute, McGill University, Montréal, QC, Canada
- Received 12 March 2012. Revised 22 July 2012. Accepted 24 July 2012. Available online 10 August 2012.
- Corresponding author at: Centre for Research in Human Development, Concordia University, 7141 Sherbrooke Street West, Montréal, QC H4B 1R6, Canada. Tel.: +1 514 848 2424x7543; fax: +1 514 848 2815.