Mitochondrial dysfunction induced by pancreatitis-associated ascitic fluid

Acute hemorrhagic pancreatitis (AHP) involves multiple organ failure probably caused by the toxic factor(s) released in pancreatitis-associated ascitic fluid (PAAF). We found that PAAF interferes with hepatic mitochondrial respiration resulting in severe disturbances in respiratory control (RCR) and ADP/O ratios. Pancreatitis was induced in dogs by retrograde pancreatic duct infusion and the resultant PAAF was centrifuged, filtered, and frozen until used. Two human PAAFs collected from AHP patients were treated in a similar manner. Rat liver mitochondrial oxygen uptake was measured at 30 degrees C before and after addition of ADP and PAAF. Paired control runs were made using pooled heat-inactivated dog serum. Tests with nine canine PAAFs showed a mean increase of 120% in state 4 respiration (P less than 0.0001). After exposure to PAAF, addition of ADP to previously coupled mitochondria did not induce state 3 respiration. The human PAAFs both showed significant increases in state 4 respiration (P less than 0.01) and a marked decrease in RCR. Dose-response tests with human and canine PAAFs showed a positive correlation between percentage increase in state 4 respiration and the concentration of PAAF used. These results confirm the presence in PAAF of mitotoxic substance(s) which cause irreversible mitochondrial damage. Inhibition of coupled mitochondrial respiration by PAAF with the resultant fall in ATP may be the causative agent for the tissue and organ damage observed in AHP.