On the production of hyperglycæmia and glycosuria by magnesium salts

Abstract

In their experiments on the action of magnesium salts, Meltzer and Auer observed that after subcutaneous injections of magnesium sulphate the urine of rabbits contains a reducing substance. Underhill and Closson, who later noticed the presence of hyperglycæmia after an intravenous injection of magnesium sulphate, ascribed the hyperglycæmia to the asphyxia which the magnesium salts produced in their experiment.

In a series of experiments which we have recently carried out on dogs, all the animals had from the beginning to the end of the experiment either intratracheal insufflation or the usual artificial respiration. The occurrence of asphyxia was thus excluded. The operative part was done under local anesthesia. In most of the experiments an M/4 solution of magnesium sulphate was injected intravenously. There was a considerable increase of the sugar content of the blood after the infusion practically in all experiments. In most cases the original glycæmia did not exceed 0.13 per cent., while at the end of the injection or some time later, the sugar content of the blood was often as high as 0.4 per cent. and even higher. In blood taken about an hour and a half after the end of an injection the glycæmia was iound often to have dropped to the original content.

There can be no doubt that magnesium sulphate produces considerable hyperglyczmia which is not due to asphyxia; it is produced in some way specifically by the magnesium salt, Sodium sulphate does not affect the normal glyczmia.

It is a noteworthy fact that the glycosuria was very little marked and far under proportion to the hyperglyczemia. Glycosuria was often entirely absent and when present it never reached even 1/2 per cent. The intravenous injection of magnesium sulphate also produced very little diuresis.