Normal and alloxan diabetic rats were injected with DL-lactate-l-C-14, DL-lactate-2-C-14 and L(+) lactate-l-C-14 and the total excretion of radioactivity determined. The uncontrolled diabetic rat expired about 15–20 per cent less C-14-O2 than the normal animals. The diabetic animals excreted about twice as much radioactivity in the urine as the normal animals; in these diabetic animals essentially all of the radioactivity was found in glucose.
After evaluation of all the possible reasons for the difference in amount of C-14-O2 expired by normal and diabetic animals it was concluded that lactate is metabolized at essentially the same rate in both animals but that in the diabetic animal, a greater portion of the carbon atoms of lactate is incorporated into glucose and less converted to CO2.
