Thiamine transport by human intestine in vitro.

Surgical specimens of human gastrointestinal mucosa and mucosa and muscle were incubated in vitro with thiamine-thiazole-214 C. Labelled thiamine uptake was uphill in mucosal tissues and downhill in muscle. Small intestinal mucosa accumulated labelled thiamine in a phosphorylated form, while gastric and colonic mucosa, as well an muscular layers of all gastrointestinal segments studied, did not.