Participation of corticotropin-releasing factor type 2 receptors in the acute, chronic and withdrawal actions of nicotine associated with feeding behavior in rats.
We investigated the role of corticotropin-releasing factor type 2 (CRF(2)) receptors in acute, chronic and withdrawal effects of nicotine on feeding behavior in rats. Nicotine was injected intraperitoneally, whereas CRF, CRF(2) 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 4h 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 CRF(2) receptors, within the framework of PVN, may contribute to the acute, chronic and withdrawal responses of nicotine on feeding and body weight.
Kamdi
Sandesh P
SP
Department of Pharmaceutical Sciences, Rashtrasant Tukadoji Maharaj Nagpur University Campus, Amravati Road, Nagpur, Maharashtra 440033, India.
Nakhate
Kartik T
KT
Dandekar
Manoj P
MP
Kokare
Dadasaheb M
DM
Subhedar
Nishikant K
NK
D000818:Animals; D000855:Anorexia / Q000139:chemically induced; D003346:Corticotropin-Releasing Hormone / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects*; D006963:Hyperphagia / Q000209:etiology; D007274:Injections, Intraperitoneal; D007700:Kinetics; D008297:Male; D009538:Nicotine / Q000008:administration & dosage*; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000502:physiology; D010446:Peptide Fragments / Q000008:administration & dosage; D010456:Peptides, Cyclic / Q000008:administration & dosage; D051381:Rats; D017207:Rats, Sprague-Dawley; D018019:Receptors, Corticotropin-Releasing Hormone / Q000819:agonists / Q000037:antagonists & inhibitors / Q000502:physiology*; D013375:Substance Withdrawal Syndrome; D054832:Urocortins / Q000008:administration & dosage; D015430:Weight Gain; D015431:Weight Loss
C101531:CRF receptor type 2; D010446:Peptide Fragments; D010456:Peptides, Cyclic; D018019:Receptors, Corticotropin-Releasing Hormone; D054832:Urocortins; C528574:astressin-2B; D009538:Nicotine; D003346:Corticotropin-Releasing Hormone