Variations in Plasma Glucose in Normal Subjects and Diabetics in the Fasting State

Abstract

Abstract. In 23 normal subjects and seven juvenile diabetics the plasma level of glucose has been determined at 30‐sec intervals under basal conditions. In seven of the normal persons venous blood was studied, in the remaining subjects arterial blood. Only arterial blood was studied in the diabetic group. In some, but not all, of the subjects the variations in the glucose level significantly exceeded the error of the measurement. There were short‐lasting, irregular undulations in the gluose concentration of an amplitude of 2–8 mg/100 ml during periods of 2–6 min. There was no significant difference in glucose variations between normals and diabetics. This may be interpreted as evidence that an intact beta‐cell function is not necessary for maintaining a normal glucose homeostasis. The authors advance the hypothesis that the glucose concentration in the fasting state is regulated primarily by a feedback mechanism between glucose and the activities of the enzymes involved in the carbohydrate metabolism of the liver. This mechanism does not require normally functioning endocrine glands, only the presence of certain minimum concentrations of the glucostatic hormones, in particular insulin and possibly glucagon.

Portal and Cubital Serum Insulin During Oral, Portal and Cubital Glucose Tolerance Tests

“…in the dog. Thus, whereas the liver does not seem to exhibit any autoregulation in the case of major acute changes in plasma glucose, it cannot be ruled out that the liver exerts an autoregulatory function on minor variations in blood glucose (3,19).…”