[Ultrastructural localization of thiamine pyrophosphatase activity in the epitheliocytes of duodenal biopsies in peptic ulcer].

Using electron microscopic studies the location of thiamine pyrophosphatase (TPPase) activity in the epithelial cells of duodenal mucosa was investigated in 39 patients with ulcer exacerbation and during the disease remission. The biopsy material was studied before and after the administration of physiological and therapeutic doses of thiamine. TPPase activity was detected on the membranes of Golgi complex, lateral cell membrane and microvilli. The possibility of intra- and extracellular localization of TPPase activity and the activity of various enzymes depending on the mechanism of thiamine absorption across the epithelial barrier is discussed.