On elimination through the mucosa of the urinary bladder

Abstract

In a previous communication (Journal of Exper. Medicine, XIV, 274, 1911), I stated that after intravenous injections of large amounts of dextrose the intestine contained on the average 1.2 per cent. of the injected amount of destrose and in nephrectomized animals the dextrose content of the intestine reached the average of 2.2 per cent. The question arose then whether in the presence of a strong hyperglycemia, and especially after double nephrectomy, all mucous membranes are slightly permeable to this substance. The presence of measurable quantities of dextrose in the gastro-intestinal canal is no evidence for the permeability of the mucosa as such, since the mucous membrane of this organ is studded with numerous glandular structures which may readily be instrumental in the removal from the blood of substances present there in excess. In the experiments I wish to communicate here, I selected, therefore, the bladder for the study of this problem since the mucous lining of this organ is practically the only membrane which possesses no glands. The rabbit was the experimental animal used.

After performing a double nephrectomy and tying a cannula in the bladder, seven to ten grams of dextrose per kilogram were injected intravenously in from twenty to fifty minutes, washing the bladder several times during and after the injection. The washings were then analyzed. The results are briefly as follows. In nine experiments either no sugar or else indeterminable amounts were found, and in four experiments only six to eleven milligrams, i. e., 0.05 to 0.08 per cent. of the amount injected. In addition, in some of the experiments uranine, the sodium salt of fluorescei'n, was dissolved in the injection fluid. In the experiments in which twenty milligrams were introduced, no trace of uranine, a very diffusible dye, could be detected in the washings of the bladder.