['The disturbance of mitochondrial functions has been considered as one of the mechanisms of pathogenesis of acute pancreatitis (AP) followed by kidney failure. This study was aimed to investigate the effects of methylene blue (MB) on pancreas and kidney mitochondrial respiratory functions during experimental acute pancreatitis in rats.', 'AP was induced by administrating sodium taurocholate into the pancreatic duct of male Wistar rats. The rats were divided into three groups: the MB group, MB (5\u2009mg/kg) was injected intravenously 10\u2009min prior to AP induction; the AP group, saline solution was injected intravenously 10\u2009min prior to AP induction; and the sham operation group, isotonic sodium chlorine was used instead of sodium taurocholate. The animals were sacrificed after 24\u2009h. The pancreas and kidney were removed for mitochondrial assay by oxygraphic and spectrophotometric methods.', 'Intravenous injection of MB did not prevent AP-induced inhibition of pancreatic mitochondrial respiration; however, MB significantly improved kidney mitochondrial respiratory functions with complex I-dependent substrates glutamate and malate. The activity of complex I of mitochondria isolated from AP-damaged kidney was increased after pretreatment with MB. However, MB did not affect AP-inhibited kidney mitochondrial respiration with succinate. MB had no protective effects on amylase activity or on urea content in serum in AP.'] Does methylene blue attenuate mitochondrial dysfunction of rat kidney during experimental acute pancreatitis?