THE EFFECT OF INSULIN, PITUITRIN AND ADRENALIN ON THE BLOOD-SUGAR LEVEL 1

Abstract

In normal rabbits insulin caused a fall in blood sugar concentration followed by a rise to normal, pituitary extract and adrenalin a rise followed by a fall to normal or below; the blood sugar curves obtained with insulin and pituitary extract were almost directly the reverse of one another. Blood sugar curves obtained with adrenalin were not so directly the reverse of those obtained with insulin, and differed from those obtained with pituitary extract in that the resultant hyperglycemia was of longer duration and subsided more gradually. From transfusion experiments it appears that the rapid fall in blood sugar concentration following injection of pituitrin is due to a recognizable increase in the circulating insulin, while the gradual fall following the injection of adrenalin is not due to this cause. Injections of "insulinized" or "pituitrinized" blood was followed by slight hypo-glycemia. Injection of normal blood, of "adrenalinized" blood, or of blood made hyperglycemic by glucose was followed by slight hyperglycemia. These experiments bear out the views of Burn in regard to the antagonism which exists between extract of the posterior lobe of the pituitary gland and insulin, and offer a possible explanation for the antagonism between pituitrin and adrenalin noted by Stenstiom.