Influence of exogenously administered oxytocin on the corticosterone and prolactin response to psychological stress.
Prolactin along with corticosterone is a stress responsive hormone. Evidence suggests that oxytocin (OXT) modulates not only ACTH secretion but also prolactin release. The present study was therefore designed to examine the possible role of oxytocin in the corticosterone and prolactin response to predictable and unpredictable novelty stress. Repeated stress and oxytocin treatment produced a substantial increase in corticosterone. A greater increase was obtained for the larger OXT dose (11.6 IU/kg) than for the smaller dose (5.8 IU/kg). In addition, for the smaller oxytocin dose only, unpredictable exposure to the novelty apparatus produced a more substantial increase in corticosterone than predictable exposure to the same stressor. In contrast, oxytocin produced a significant suppression of the prolactin response in all OXT treated animals. No significant interaction between stress and oxytocin was obtained. It was concluded that an important role exists for oxytocin in the modulation of both corticosterone and prolactin secretion.
Muir
J L
JL
Department of Psychology, University of Newcastle N.S.W., Australia.
Pfister
H P
HP
D015062:11-Hydroxycorticosteroids / Q000378:metabolism; D000818:Animals; D003345:Corticosterone / Q000378:metabolism*; D005106:Exploratory Behavior; D005260:Female; D010121:Oxytocin / Q000494:pharmacology* / Q000502:physiology; D011388:Prolactin / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013315:Stress, Psychological / Q000503:physiopathology*
D015062:11-Hydroxycorticosteroids; D010121:Oxytocin; D011388:Prolactin; D003345:Corticosterone