title: Gender differences in Nociceptin/Orphanin FQ-induced food intake in strains derived from rats prone (WOKW) and resistant (Dark Agouti) to metabolic syndrome: a possible involvement of the cocaine- and amphetamine-regulated transcript system.
abstract: Our previous study found that when injected with Nociceptin/Orphanin FQ (N/OFQ) into the brain, male Dark Agouti (DA) rats, which are resistant to metabolic syndrome, have greater hyperphagia than male Wistar Ottawa Karlsburg W (WOKW) animals, which are prone to this disease. We attributed this difference to the fact that these two strains have different cocaine-amphetamine regulated transcript peptide (Cart) gene sequences and expression. In order to address this hypothesis, the present work focused on sex differences and analyzed not only male but also female N/OFQ-induced (0.25 and 0.5 nmol/rat) food intake in terms of their Cart and N/OFQ receptor gene expression in the hypothalamic area. In N/OFQ-naive WOKW females, cart gene expression is extremely elevated compared to N/OFQ-naive WOKW males. When male and female WOKW littermates are stimulated with N/OFQ, the food intake of females is significantly lower than that of the males. Granted, the N/OFQ feeding behavior experiments were not performed on the animals measured for Cart gene expression, but nonetheless, the responses observed in littermates point to an interesting avenue for further inquiry.
authors.affiliation: Department of Experimental Medicine and Public Health, University of Camerino, Via Madonna delle Carceri, 62032, Camerino, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Battistoni
authors.forename: Ingrid
authors.initials: I
authors.lastname: Kloting
authors.forename: Carlo
authors.initials: C
authors.lastname: Cifani
authors.forename: Maurizio
authors.initials: M
authors.lastname: Massi
authors.forename: Carlo
authors.initials: C
authors.lastname: Polidori