DETECTION OF ALPHA-HYDROXYETHYL FREE-RADICAL ADDUCTS IN THE PANCREAS AFTER CHRONIC EXPOSURE TO ALCOHOL IN THE RAT

Chronic pancreatitis is characterized by inflammation and fibrosis lea ding to tissue destruction; in industrialized nations, alcohol abuse i s the cause of 70-80% of cases of pancreatitis in adults. The purpose of the current work was to determine whether free radical adducts are produced by the pancreas during Vie early phases of chronic exposure t o ethanol. Accordingly, rats were chronically led ethanol using the mo del of continuous enteral infusion developed by Tsukamoto et al. [Am. J, Physiol. 247: R595-R599 (1984)], Histological evaluation revealed o nly mild acinar steatosis and spotty necrosis after 4 weeks of alcohol treatment; the pancreatic enzymes lipase and amylase were not elevate d, Furthermore, no fibrosis was detected, nor were there differences i n pancreatic collagen alpha 1(I) mRNA levels between ?he dietary contr ol and ethanol-treated groups. After 4 weeks, rats were injected with the spin trap alpha-(4-pyridyl-1-oxide)-N-tert-butylnitrone (1 g/kg in travenously), and pancreatic secretions were collected over a 4-hr per iod. A six-line free radical adduct spectrum indicative of a carbon-ce ntered free radical was detected in pancreatic secretions and in Folch extracts of pancreatic tissue by electron spin resonance spectroscopy . Control experiments ruled out ex vivo radical formation. This study represents the first detection of radical adducts in pancreatic secret ions. When [C-13]ethanol (3 g/kg intragastrically) was administered, a definitive 12-line spectrum was detected in pancreatic secretions, de monstrating that the alpha-hydroxyethyl radical adduct was formed in t he pancreas from [C-13]ethanol. interestingly only a six-line signal w as detected in tissue extracts under these conditions. Free radicals, therefore, are formed in the pancreas during the early phases of chron ic alcohol intake in rats before the development of overt pathology.