On the nature of pancreatic diabetes. (Preliminary communication)
Many explanations have been proposed for the fact, discovered by von Mering and Minkowski (1), that extirpation of the pancreas is followed immediately by severe and fatal diabetes. It has been suggested on the one hand that the normal function of the pancreas is to diminish excessive production of sugar, and that, in the absence of its restraining influence, excessive sugar production and mobilisation are the results. On the other hand, the fact that carbohydrates are not utilised by the body when administered to animals in this condition has been interpreted as showing that the tissues have lost their normal power of assimilating and utilising glucose. It has also been suggested, though without much experimental support, that the sugar of the blood has to be built up into some other form before it can be utilised by the tissues. We have recently, in a research on the influence of mechanical conditions and of temperature on the heart beat, modified the procedure described by Jerusalem and Starling (2) for working with a heart-lung preparation, so that we are able to keep a heart, connected with the lungs but isolated from the rest of the body, beating for many hours in approximately normal conditions, i . e . working at a normal arterial pressure and with a normal output. In this preparation we are able to vary at will the venous filling of the heart, the arterial resistance, or the temperature. The total amount of blood employed is about 300 c. c., and as the heart of a small dog puts out about 150 to 250 c. c. of blood per minute, the whole of the blood in the apparatus circulates through the heart once in every two minutes. It occurred to us that it might be possible by using this preparation to throw i light on the pathogeny of pancreatic diabetes.