[Modification of alcohol-induced pancreatic damage in rats by soybean diet]

Alcohol-induced hypersecretion probably contributes to chronic alcoholic pancreatitis. Feeding of raw soybean flour or soybean trypsin inhibitor also stimulates protein secretion of the pancreas. Therefore, we tested whether or not the pancreatic damage is increased by additional feeding of raw soybean flour in rats fed 20% ethanol. After 11 months, we classified the morphological lesions of the pancreas into seven stages of severity calculated by means of a discriminating procedure. In order to characterize the secretory capacity of the pancreas, we measured the outputs of lipase, phospholipase, A, alpha-amylase, carboxypeptidase A, chymotrypsin, and bicarbonate. Compared with the alcohol-fed animals, the rats fed with alcohol and soya exhibited a lower average degree of morphological damage in the pancreas. Hypertrophy and hyperplasia of the parenchyma and accumulation of secretory products within the acinar cells were main features. On the other hand, some separate regions of the pancreas showed intraductal secretion precipitates as well as plugs, which were sometimes associated with atrophy of acinar cells. Feeding with soybean diet grossly reduced the alcohol-induced enzyme hypersecretion. In the early phase of alcohol-induced pancreatic damage, long-term soybean flour diet thus reduces morphological lesions and hypersecretion of the rat pancreas, whereas protein synthesis in the acinar cells appears increased. However, the precipitation of secretory products on ductal epithelium, the increased formation of plugs, and the more frequent acinar atrophies suggest the development of significant tissue injuries.