A Reversible Experimental Uremia

Abstract

If the vena cava in ♀ albino rats is ligated and cut immediately above the entry of the renal veins there is a temporary cessation of renal function and the blood urea rises to very high levels. By the end of the second day a urine is voided which looks like water. It contains a high concentration of protein and many renal failure casts. Ninety day old rats were used. They were taken from the usual stock diet for the colony, operated upon and given only distilled water after the operation. Groups of 8 or 10 were sacrificed at intervals of from one to 6 days after the operation. The average concentration of blood urea, mgm. per 100 cc., on these various days was as follows: On the first day 268, on the second 413, on the third 278, on the fourth 63, on the fifth 55, and on the sixth 31. These rats excreted normally from 2 to 4 mgm. of protein in the urine in 24 hours but during the first and second days following the operation they excreted from 40 to 55 mgm. per 24 hours. Of the 57 rats used in this part of the work 2 died, giving a mortality of 3.5%. As controls similar animals had the same operative procedure carried out except that the vena cava was not ligated or cut, or it was ligated and cut immediately below the entry of the renal veins. The highest concentration of blood urea found in these animals was 34 mgm. per 100 cc., there was little or no increase in the amount of protein excreted, and none of them died.

This form of experimental uremia on account of its reversibility and the relative simplicity of its causation, is particularly adapted for the quantitative analysis of certain aspects of the general problem of uremia.