Given the prevalence of metabolic syndrome inolder adults and the detrimental impact of metabolic syndrome especially obesity onlife expectancy and comorbidity in the elderly [24], the present study wasdesigned to evaluate the influence of aging on basal and leptin-elicited cardiaccontractile response in the leptin-deficient ob/ob mice. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.