[Effect of biguanids on the lactate metabolism. Studies in diabetics under submaximal ergometric exercise (author's transl)].

24 diabetics without any complications were subjected to an exercise test before and after biguanid therapy. The schedule of the physical strain was a modification of the Kaltenbach diagram. Changes of lactate, pyruvate, pH-standard bicarbonate and base excess values were analysed. Additionally to antidiabetical therapy each of the 8 patients was given either metformin or buformin or phenformin now. Each one of the biguanid derivates induced a rise of the lactate level before and after the exercise test. Phenformin showed the greatest influence on the lactate metabolism, metformin the smallest. Reasons causing the lactogene effect and the quantitative differences of the biguanides are discussed.