Ethanol-Mediated Neutrophil Extravasation in Feline Pancreas

Ethanol is a common cause of both acute andchronic pancreatitis. Studies in other organs suggestthat polymorphonuclear neutrophils activated by ethanolmay cause tissue injury in a variety of conditions. The aim of this study was to investigate theeffects of ethanol on neutrophil extravasation in thefeline pancreas. Pancreata were isolated and perfused atdifferent flow rates with varying concentrations of ethanol in either a physiological orneutrophil depleted perfusate. Neutrophil extravasationwas assessed by measuring pancreatic tissuemyeloperoxidase (MPO) activity. Ethanol at 2.5 (54.25mmol/liter) was the lowest concentration that still causedsignificant neutrophil extravasation (3.1 ± 0.8vs 1.9 ± 0.2 units, P < 0.05) and wasaccompanied by an increase in vascular resistance of15%. Reduction of pancreatic perfusion by 15% did notsignificantly increase neutrophil extravasation. (1.1± 0.3 vs 1.6 ± 0.2 units, NS) Perfusion ofthe pancreas with neutrophil-depleted blood containingeither ethanol or saline, followed by perfusion withan ethanol-free perfusate, showed an increase inneutrophil extravasation in the ethanol group comparedto the control group (3.2 ± 0.9 vs 1.9 ±0.2 units, P < 0.05). In conclusion, ethanol causesneutrophil extravasation in the feline pancreasindependent of blood flow changes and occurs despite theabsence of direct neutrophil exposure toethanol.