Effects of the nonsteroidal anti-inflammatory drug nimesulide on energy metabolism in livers from adjuvant-induced arthritic rats.

The effects of nimesulide on energy metabolism and the hepatic metabolic alterations produced by adjuvant-induced arthritis were investigated in the perfused rat liver an in isolated liver mitochondria. Nimesulide, at therapeutic levels (20-50 microM), produced: (1) stimulation of oxygen consumption in the perfused rat liver and in isolated mitochondria, (2) inhibition of gluconeogenesis; (3) reduction of ADP/O ratio and the respiratory control ratio and stimulation of glycogenolysis in the livers from healthy rats, but not in livers from arthritic rats. These results indicate that nimesulide acts as a mitochondrial uncoupler. The main alterations produced by adjuvant-induced arthritis were: higher rates of oxygen consumption in both perfused livers and isolated mitochondria, with no decrease in the efficiency of mitochondrial energy transduction; (2) decreased gluconeogenesis and lack of glycogenolytic response to uncouplers, but not to alpha 1-agonists. These data allow to conclude that nimesulide-induced impairment of energy metabolism should worsen the hepatic disturbances that are already associated with the adjuvant disease.