Glucose tolerance tests (GTT) have bee nextensively used for the study of carbohydrate metabolism in both experimental and clinical work. The oral GTT suffers from the disadvantage that the changes in the blood glucose during the test depend to a large extent on the magnitude of the amount absorbed and the rate of intestinal absorption of glucose.1 By the intravenous administration of glucose this is eliminated and, hence, the intravenous GTT has been more extensively employed during the last few years.
Many different techniques have been described for the performance of the intravenous GTT (see Ross, 1938, Tunbridge & Allibone, 1940, Goldberg & Luft, 1948, 1949, Conard, 1955). Jörgensen & Plum (1923) studied the changes in blood glucose after an intravenous injection (during 3–5 minutes) of 20 gm. of glucose. Because of its convenience this »rapid« intravenous GTT has been used by many workers, although criticisms have also been