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Involvement of Prolactin‐Releasing Peptide in the Activation of Oxytocin Neurones in Response to Food Intake
Author(s) -
Yamashita M.,
Takayanagi Y.,
Yoshida M.,
Nishimori K.,
Kusama M.,
Onaka T.
Publication year - 2013
Publication title -
journal of neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.062
H-Index - 116
eISSN - 1365-2826
pISSN - 0953-8194
DOI - 10.1111/jne.12019
Subject(s) - oxytocin , medicine , endocrinology , prolactin , food intake , peptide , neuropeptide , peptide hormone , psychology , biology , hormone , receptor , biochemistry
Food intake activates neurones expressing prolactin‐releasing peptide (Pr RP ) in the medulla oblongata and oxytocin neurones in the hypothalamus. Both Pr RP and oxytocin have been shown to have an anorexic action. In the present study, we investigated whether the activation of oxytocin neurones following food intake is mediated by Pr RP . We first examined the expression of Pr RP receptors (also known as GPR 10) in rats. Immunoreactivity of Pr RP receptors was observed in oxytocin neurones and in vasopressin neurones in the paraventricular and supraoptic nuclei of the hypothalamus and in the bed nucleus of the stria terminalis. Application of Pr RP to isolated supraoptic nuclei facilitated the release of oxytocin and vasopressin. In mice, re‐feeding increased the expression of Fos protein in oxytocin neurones of the hypothalamus and bed nucleus of the stria terminalis. The increased expression of Fos protein in oxytocin neurones following re‐feeding or i.p. administration of cholecystokinin octapeptide ( CCK ), a peripheral satiety factor, was impaired in Pr RP ‐deficient mice. CCK ‐induced oxytocin increase in plasma was also impaired in Pr RP ‐deficient mice. Furthermore, oxytocin receptor‐deficient mice showed an increased meal size, as reported in Pr RP ‐deficient mice and in CCK A receptor‐deficient mice. These findings suggest that Pr RP mediates, at least in part, the activation of oxytocin neurones in response to food intake, and that the CCK –Pr RP –oxytocin pathway plays an important role in the control of the termination of each meal.