Metabolism in abdominal organs, as evaluated by microdialysis, in experimental severe acute pancreatitis

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Introduction

Septic states might induce regional variations in metabolism. The aim of the present study was to evaluate if regional metabolic differences could be identified in a model of severe acute pancreatitis in the rat, with the use of a microdialysis technique.

Methods

Under full anesthesia, microdialysis probes were inserted in the parenchyma of the pancreas and liver and under the serosa of the small intestine. Microdialysate was collected every 10 min. After a baseline period of 60 min, acute pancreatitis was induced by intraductal injection of 0.20–0.29 ml 5% sodium taurodeoxycholate. The animals were studied for three h after induction of pancreatitis after which they were killed. Arterial blood samples were taken every 60 min. The microdialysis fluid and blood were analyzed for glucose and lactate. Six groups were studied with six animals in each group; Sham, Pancreatitis and four groups with treatment given 15 min after induction of acute pancreatitis (early treatment). Treatment administered included N-acetylcystein (NAC; 200 mg/kg i.v), a platelet-activating factor (PAF) antagonist (lexipafant, 5 mg/kg) and monoclonal antibodies against the adhesion molecules ICAM-1(0.2 mg) and PECAM-1 (0.2 mg).

Results

The levels of lactate and glucose in pancreas and lactate in blood were higher (P<0.05) in the pancreatitis group compared with the sham group. The increases of glucose and lactate in the pancreas were higher than in the blood, demonstrating an earlier and stronger change in metabolism in the pancreas as compared with the rest of the body. This finding was higher (P<0.05) in the pancreatitis group than in the sham group. There were no clear differences between the various pancreatitis groups, with or without treatment. and no differences in between the treatment groups. Within the sham group, glucose showed no regional difference, but there was a significant increase in the pancreas in pancreatitis animals as compared to the liver and intestine. Regarding lactate, there were differences between the pancreas, liver and intestine in both groups with higher levels seen in the pancreas.

Conclusion

An increase in pancreatic lactate concentrations in pancreatitis animals was seen and this increase seemed to have its origin in the pancreas and not in the whole body. Similar changes were also found for glucose. Early treatment, as described earlier, had no obvious effect on these parameters. The results imply that micro-dialysis could be of potential future value in monitoring metabolic locoregional differences in critical illness.