Z Gastroenterol 2010; 48 - A3
DOI: 10.1055/s-0030-1254741

Investigation of cocaine- and amphetamine-regulated transcript (CART) peptide immunoreactivity in feeding-related brain areas of CCK-1 receptor deficient rats

S Armbruszt 1, H Abraham 2, M Figler 3, A Hajnal 4
  • 1Department of Nutritional Sciences and Dietetics, Faculty of Health Sciences, University of Pécs, Hungary
  • 2Central Electron Microscopic Laboratory, Faculty of Medicine, University of Pécs, Hungary
  • 32nd Department of Internal Medicine and Nephrology Center, Pécs, Hungary
  • 4Department of Neural and Behavioral Sciences, College of Medicine, The Pennsylvania State University, Hershey, PA, USA

Introduction: Cholecystokinin (CCK) mediates digestion and has stimulatory effects on the vagus nerve, induces satiation by decreasing the rate of gastric emptying. Naturally occurring mutation of the CCK-1 receptor gene in the Otsuka Long Evans Tokushima Fatty (OLETF) rats results in hyperphagia, obesity and the development of type II diabetes. Cocaine- and amphetamine regulated transcript (CART) peptide is expressed in the myenteric plexuses of small and large intestine, as well as in brain areas involved in the control of appetite and has an overall anorexigenic effect. Recently, we have shown that CART immunoreactivity (ir) was significantly reduced in the rostral part of the nucleus accumbens and in the rostro-medial nucleus of the solitary tract in diabetic OLETF rats compared to Long Evans Tokushima Otsuka (LETO) lean controls, whereas distribution of CART-ir elements in the brain was identical.

Methods: In the present study, CART-immunoreaction in feeding-related areas of the brain was compared in age-matched (6–8 weeks old) non-obese OLETF rats and in LETO lean controls.

Results: Like in adult rats, no difference was detected in the young OLETF and LETO strains in the distribution and intensity of CART-ir in areas related to food intake regulation such as nucleus accumbens, septal and hypothalamic nuclei, amygdala, parabrachial nucleus and nucleus of the solitary tract. Thus, in contrast to the adult diabetic rats, CART-peptide expression is not decreased in the nucleus of solitary tract and in nucleus accumbens of non-obese non-diabetic OLETF compared to control LETO rats.

Discussion: These findings collectively suggest that factors related to obesity and/or diabetes rather than impaired CCK-1 receptor signaling may contribute to altered CART expression in this strain.

Supported by the Hungarian State Eötvös Scholarship and grant of the University of Pecs ÁOKKA-34039–4/2009 to H.A., and NIH grant DK065709 to A.H.