Participation of corticotropin-releasing factor type 2 receptors in the acute, chronic and withdrawal actions of nicotine associated with feeding behavior in rats

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• 作者：S ; esh P. Kamdi ; Kartik T. Nakhate ; Manoj P. D ; ekar ; Dadasaheb M. Kokare ; Nishikant K. Subhedar
• 关键词：Nicotine ; CRF₂ receptor ; Urocortin ; Food intake ; Body weight
• 刊名：Appetite (APPET)
• 出版年：2009
• 出版时间：December 2009
• 年：2009
• 卷：53
• 期：3
• 页码：354-362
• 全文大小：811 K

文摘

We investigated the role of corticotropin-releasing factor type 2 (CRF₂) receptors in acute, chronic and withdrawal effects of nicotine on feeding behavior in rats. Nicotine was injected intraperitoneally, whereas CRF, CRF₂ receptors agonist urocortin-1 or selective antagonist astressin2-B were administered directly into the hypothalamic paraventricular nucleus (PVN). In acute studies, nicotine, CRF or urocortin-1 produced dose dependent anorexia at 2 and 4 h post-injection time-points, however, astressin2-B did not alter the food intake. Prior treatment of CRF or urocortin-1 potentiated the anorectic effect of nicotine, while astressin2-B showed opposite response. Chronic administration of nicotine produced tolerance to anorexia and caused persistent weight loss. However, concomitant treatment with CRF or urocortin-1 resulted in early tolerance to nicotine-induced anorexia. In the same set of animals, while CRF pre-treatment potentiated the weight reducing effect of nicotine, urocortin-1 failed to do so. Although abrupt termination of chronic nicotine treatment caused hyperphagia and weight gain, administration of CRF or urocortin-1 prevented these effects. These results suggest that CRF₂ receptors, within the framework of PVN, may contribute to the acute, chronic and withdrawal responses of nicotine on feeding and body weight.