Alcohol dehydrogenase (ADH) isoenzymes and aldehyde dehydrogenase (ALDH) activity in the human pancreas

Ethanol metabolism in the pancreas occurs predominantly by way of an nonoxidative pathway to fatty acid ethyl esters but oxidative routes to acetaldehyde also may contribute to injury of pancreatic cells. Three metabolic systems are responsible for the oxidative metabolism of ethanol, among which the cytochrome P-4502E1 and alcohol dehydrogenase have been found in the pancreas. The aims of this study were to detect ADH and ALDH in the human pancreas and to assess which ADH isoenzymes are present in this organ. ADH activity was measured by the photometric method and ADH isoenzyme activity was determined using sensitive and specific substrates. ALDH activity was measured by the fluorometric method. We have shown that the activities of ADH and ALDH are present in the pancreas, although the activity of ALDH was not proportionally as low as ADH activity. The class III isoenzyme exhibited the highest activity of all ADH isoenzymes tested and it was about 7 times higher than the activity of class I. The activities of classes II and IV were low. The activities of ADH isoenzymes of classes I, II, and III in the pancreas of men were significantly higher than in women. This study demonstrates that alcohol dehydrogenase and aldehyde dehydrogenase are present in the pancreas.