Studies on the Site and Mechanism of Action of Phenformin: II. Phenformin Inhibition of Glucose Transport by Rat Intestine

The effect of oral phenformin on the active transport of glucose by everted sacs of rat intestine was investigated. Pretreatment of the animals with a single dose of the drug resulted in an inhibition of active transport. A log-dose relationship was found in the range studied (5 to 150 mg./kg.). These findings could explain the observation that phenformin increases the tolerance to orally administered glucose but has no effect on intravenous glucose tolerance in humans.