[Labelled 35S-thiamine distribution and secretion in the digestive system of rats of different ages]

The labelled thiamin, administered intravenously, was accumulated mainly in liver tissue and small intestinal wall of 24 months old rats as compared with 3 months old rats. Secretion of metabolites of the labelled thiamin was distinctly decreased in the stomach of old animals. A decrease in secretion and reabsorption of metabolites of the administered thiamin in stomach might be a response to inhibition of the liver-intestinal circulation of thiamin as well as to its transport-metabolic turnover in tissues of the gastro-intestinal tract.