EXPERIMENTAL RENAL INSUFFICIENCY PRODUCED BY PARTIAL NEPHRECTOMY: VIII. COMPARISON OF THE UREA (ADDIS) RATIO WITH RESULTS OF OTHER TESTS OF RENAL FUNCTION

Our purpose in this paper is to compare the blood urea concentration and blood pressure and the specific gravity, volume and protein content of urine collected during a concentration test with the urea ratio in partially nephrectomized rats fed diets containing different amounts of whole dried meat. In recent years the urea clearance has been compared with the concentration of urea,¹ and of creatinine^1b in the blood, hemoglobin content,^1b phenolsulfonphthalein excretion,^{1b, e} urinary specific gravity² and³ ratio. In the experiments reorted by nonprotein nitrogen L Addis⁴ and Van Slyke⁵ the ability of the kidneys to excrete urea appeared to be the most sensitive indicator of the state of renal function. —MacKay and MacKay^la and Van Slyke and his co-workerslb found that the urea concentration of the blood did not rise appreciably until the active kidney tissue was reduced one-half as measured by the urea clearance in patients