[The characteristics of the action of calcium antagonists on glucose transport in the rat small intestine].

Ca antagonists reduced intestinal glucose transport in vitro and in vivo. The Ca-channel blocking agent verapamil (B) and calmodulin inhibitors chlorpromazine, triftasine (I) exerted rather unequal effects on glucose transport: B exerting a weaker effect on the transport from serosa than I. B and Ca-free medium reduced Vmax with no changes at Km as opposed to I. Under the influence of EDTA (5 mmol/l) there only is an unsaturated glucose transport. Ca- and calmodulin-affinity sites seem to play a major role in the regulation of enterocyte glucose transport system.