PERIPHERAL LEPTIN ADMINISTRATION COULD NOT CHANGE INFLAMMATORY MARKERS IN ENERGY RESTRICTED RATS

Chronic inflammation involves in aging through increasing the production of cytokines and adipocytokines. Leptm is a major adipokine which studies supported its initiator role of inflammation in vitro, in the local environment of adipose tissue and systemically. Energy restriction (ER) as an anti-aging proven method modifies adipose derived proinflammatory mediators like TNF-α and IL-6. In this study it was hypothesized that whether leptm administration after chronic ER could negate the beneficial effects of ER on inflammatory markers or not. Two groups of male Wistar rats randomly divided to receive 40% ER or ad libitum food intake (AL) for 11 weeks. Then each group was divided randomly to receive 0.05mg/kg/d intravenous leptm or saline for 3 days. After ER phase, IL-6 serum levels were lower and marginally significant in ER compare to AL group (34.83±15.22ng!mL vs. 58.19±21.61 ng/mL). After leptin treatment, no statistically significant differences were observed in IL-6 and TNF-α serum levels. But IL-6 levels were significantly lower in ER groups irrespective of injection type (P=0.011), which may show the prevail effect of ER on inflammation. In conclusion this study demonstrated for the first time that peripheral leptin administration followmg chronic ER could not induce inflammatory markers in animal model.