Abstract

Oxytocin induces long-term changes in, for example, blood pressure, spontaneous motor activity and corticosterone levels in rats. Previous studies in male rats have suggested a role for alpha(2)-adrenoceptors within the central nervous system in these effects. The aim of the present study was to investigate if oxytocin treatment in female rats would influence alpha(2)-adrenoceptors within the hypothalamus, the amygdala and the nucleus of the solitary tract (NTS). For this purpose, female ovariectornized (OVX) rats were treated with oxytocin (1 mg/kg s.c.) or saline once a day for 10 days. Rats were decapitated 5 days after the last injection, and brains and plasma were collected. Quantitative receptor autoradiography for characterization of high affinity alpha(2)-adrenoceptor agonist binding and radio-immunoassay for corticosterone were performed. Oxytocin increased the B-max values of the alpha(2)-adrenoceptor agonist [3H]UK14.304 binding sites significantly in all the analyzed areas (P < 0.05). K-d values were unchanged. Plasma levels of corticosterone were significantly decreased in the oxytocin-treated rats (P < 0.05). These findings are in further support of an interaction between oxytocin receptors and alpha(2)-adrenoceptors and show that oxytocin treatment may increase alpha(2)-adrenoceptor recognition probably leading to an increase in alpha(2)-adrenoceptor signaling in several parts of the brain. (c) 2005 Published by Elsevier B.V

Published in

Brain Research
2005, Volume: 1049, number: 2, pages: 234-239
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Uvnäs-Moberg, Kerstin

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

Publication identifier

DOI: https://doi.org/10.1016/j.brainres.2005.05.034

Permanent link to this page (URI)

https://res.slu.se/id/publ/6694