2 . Mitochondrial function in leptin - deficient obese - hyperglycaemic mice [ ob / ob mice ]

This review summarises key aspects of what has been learned about the effect of leptin on mitochondrial function from studies in leptin deficient obese ob/ob mice. Ob/ob mice are grossly overweight and hyperphagic particularly at young ages. The feeding behaviour in combination with leptin deficiency leads to severe insulin resistance with hyperglycaemia and hyperinsulinemia. Mitochondrial metabolism is important in the regulation of insulin release from pancreatic ß-cells. Ob/ob mouse ß-cells respond adequately to most stimuli and ob/ob mice have been used as a rich source of pancreatic islets with high insulin release capacity. Mitochondrial metabolism is altered in leptin deficient animals leading to reduced oxidative capacity in liver and muscle cells. Uncoupling proteins are down regulated in leptin deficient mice and the production of reactive oxygen species is increased.