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Acta Physiologica 2011; Volume 202, Supplement 684
The Joint Conference (FAMÉ 2011) of the LXXVth Meeting of the Hungarian Physiological Society, XVIth Meeting of the Hungarian Society of Anatomists, Experimental Section of the Hungarian Society for Experimental and Clinical Pharmacology and Hungarian Society for Microcirculation and Vascular Biology
6/8/2011-6/11/2011
Pécs, Hungary
DIFFERENTIAL EFFECTS OF CALORIC-RESTRICTION ON LEPTIN-INDUCED HYPERMETABOLISM AND ANOREXIA IN MIDDLE-AGED (LEPTIN-RESISTANT) RATS
Abstract number: P77
Soos1 S., Lorincz1 O., Parniczky1 A., Balasko1 M., Petervari1 E., Szekely1 M.
Aims:
Catabolic effects of adipose tissue-derived leptin prevent obesity. On the one hand obesity leads to leptin-resistance at any age, on the other hand, age-related leptin-resistance promotes the progression of obesity. Our previous data showed that calorie-restriction improves leptin-responsiveness in young adult (6-months) rats. In the present study our aim was to evaluate the influence of calorie-restriction on leptin-responsiveness in middle-aged animals, in order to determine whether the reduction of fat mass may ameliorate age-related leptin-resistance.
Methods:
The effects of a 7-day long, intracerebroventricular leptin infusion (1 mg/ml/h) were measured in 2- and 12-months old ad libitum fed (normally fed: NF2, NF12) and 12-months old calorie-restricted (CR12, 16 g/day standard powdered chow) male Wistar rats. In a biotelemetric system (MiniMitter) core temperature (Tc), heart rate (HR) and spontaneous horizontal activity (ACT) were continuously recorded. Food intake (FI) and body weight (BW) were measured daily. Wet weight of the retroperitoneal and epidydimal fat pads and that of the tibialis anterior muscle were measured post mortem to evaluate the body composition of the animals.
Results:
Leptin significantly suppressed the FI and BW in NF2 and NF12 rats. The decrease in BW was more significant in young animals with low fat mass. In the CR12 group neither BW nor FI decreased significantly in response to leptin (probably due to a high orexigenic tone of chronically deprived animals). Metabolic parameters (Tc, HR) showed a different pattern. In young NF2 rats both Tc and HR were increased significantly, while NF12 animals showed minimal hypermetabolic responsiveness to leptin. The most pronounced metabolic effects were seen in the CR12 group.
Conclusions:
Our results confirm the decreased leptin-sensitivity of middle-aged rats. They also demonstrate that some components of the age-related leptin-resistance may be ameliorated, at least in part, by caloric-restriction.
Support:
OTKA PD84241, PTE AOK-KA-34039-02/2010.
To cite this abstract, please use the following information:
Acta Physiologica 2011; Volume 202, Supplement 684 :P77