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Prostaglandin mediates endotoxaemia‐induced hypophagia by activation of pro‐opiomelanocortin and corticotrophin‐releasing factor neurons in rats
Author(s) -
Rorato Rodrigo,
Menezes Aline Motta,
GiustiPaiva Alexandre,
De Castro Margaret,
AntunesRodrigues José,
Elias Lucila Leico Kagohara
Publication year - 2009
Publication title -
experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0958-0670
DOI - 10.1113/expphysiol.2008.045435
Subject(s) - endocrinology , medicine , hypophagia , corticosterone , hypothalamus , hormone , chemistry , prostaglandin , energy homeostasis , melanocyte stimulating hormone , receptor
Corticotrophin‐releasing factor (CRF) and α‐melanocyte‐stimulating hormone (α‐MSH), both of which are synthesized by hypothalamic neurons, play an essential role in the control of energy homeostasis. Neuroendocrine and behavioural responses induced by lipopolyssacharide (LPS) have been shown to involve prostaglandin‐mediated pathways. This study investigated the effects of prostaglandin on CRF and α‐MSH neuronal activities in LPS‐induced anorexia. Male Wistar rats were pretreated with indomethacin (10 mg kg −1 ; i.p .) or vehicle; 15 min later they received LPS (500 μg kg −1 ; i.p .) or saline injection. Food intake, hormone responses and Fos–CRF and Fos–α‐MSH immunoreactivity in the paraventricular and arcuate nuclei, respectively, were evaluated. In comparison with saline treatment, LPS administration induced lower food intake and increased plasma ACTH and corticosterone levels, as well as an increase in Fos–CRF and Fos–α‐MSH double‐labelled neurons in vehicle‐pretreated rats. In contrast, indomethacin treatment partly reversed the hypophagic effect, blunted the hormonal increase and blocked the Fos–CRF and Fos–α‐MSH hypothalamic double labelling increase in response to the LPS stimulus. These data demonstrate that the activation of pro‐opiomelanocortin and CRF hypothalamic neurons following LPS administration is at least partly mediated by the prostaglandin pathway and is likely to be involved in the modulation of feeding behaviour during endotoxaemia.