We used senescence-accelerated mouse prone 8 (SAMP8), a useful model of accelerated aging, to investigate the responsiveness to leptin with aging. The state of leptin-induced STAT3 phosphorylation in the hypothalamus was found to be higher in SAMP8 than in SAMR1, a control mouse showing normal aging, at 14—18 months of age but not at 2 months of age. Moreover, leptin receptor Ob-Rb expression in the hypothalamus was up-regulated in SAMP8. The results indicate that leptin sensitivity increases with aging in the SAM mouse brain.
2005 The Pharmaceutical Society of Japan