The glucose tolerance test is an important diagnostic procedure in metabolic diseases. As the test is currently employed, glucose is administered either orally or intravenously and there is no uniform interpretation of the results.A study of the rapid glucose tolerance test is found in a review by Tunbridge and Allibone (1). The present study was undertaken to test the validity of the concept that the rapid intravenous glucose tolerance test might properly and readily be interpreted by following the rate of disappearance of glucose from the blood. It was our hope also to evolve a simple test for routine use. The uniformity of the single injection method was studied as a means of separating the normal from the known mild diabetic patient. MATERIAL AND METHODSTwenty-five grams of glucose as a 30 per cent solution in distilled water were administered intravenously within four minutes. A fasting blood specimen was obtained, and then at four minutes following the glucose administration and subsequently every eight minutes for 72 minutes. Blood was obtained from an ear lobe that was kept moist with a heparin sponge. Determination of blood glucose was done by the Horvath and Knehr modification (2) of the Folin-Malmros micromethod (3).The control group consisted of 70 healthy men ranging in age from 25 to 50 years with no family history of diabetes mellitus. The test was repeated with 25 grams of glucose at intervals of from one to three months in 20 subjects, and with 35 grams of glucose in 13 who had been on an adequate carbohydrate intake. The abnormal group consisted of 26 patients with known mild diabetes mellitus controlled by diet alone (the majority had

Insulin and saline were injected into the right and left femoral arteries respectively of 19 alloxan-diabetes-mellitus dogs for 1 to 28 weeks. A significant increase of artery tissue cholesterol and total fatty acids was found on comparing the insulin-administered right leg with the saline-administered left leg. Similarly, a significant increase of total fatty acids in muscle was found on comparing the right with the left leg of the alloxan-diabetes mellitus dogs. No significant differences were observed in the normal animals when the insulin-injected side was compared with the noninjected.

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Although it is generally accepted that insulin accelerates the removal of glucose from the blood (1, 2), there has been disagreement regarding the effect of epinephrine on glucose utilization in normal individuals (2-5). The effect of hyperthyroidism on glucose tolerance tests has been found to be variable. The present study was undertaken to clarify the effects of epinephrine, insulin, and hyperthyroidism on the rate of removal of glucose from the blood of adult subjects by means of the rapid intravenous glucose tolerance test (6). MATERIAL AND METHODSAll subjects had been on a diet containing at least 150 grams of carbohydrate daily for at least one week. The rapid intravenous glucose tolerance test was carried out after a 14 hour fast, and the rate of glucose disappearance from the blood was determined as described in a previous publication (6). By this method the range of blood glucose disappearance rates in normal individuals is from 3.00 to 4.84 per cent per minute.A group of 21 normal males was employed in studying the effect of insulin and of epinephrine. A control test was performed on each subject. The test was performed in 17 of the group, 30 minutes following the subcutaneous administration of 0.5 mg. epinephrine. In a normal individual epinephrine produces a rise in the blood sugar which reaches a maximum within 25 minutes, following which there is a relative plateau for approximately 90 minutes corroborating previous work. In 18 of the group the test was performed immediately after the intravenous administration of 4 units of crystalline insulin. A time interval of approximately one month was allowed to elapse between tests in each subject.Seventeen patients with uncomplicated hyperthyroidism were studied before treatment with radioactive iodine, and the studies were repeated when a remission of the hyper-