SPECTROPHOTOMETRIC MEASUREMENT OF TRACES OF THE DYE T-1824 BY EXTRACTION WITH CELLOPHANE FROM BOTH BLOOD SERUM AND URINE OF NORMAL DOGS

¹ From the Department of Physiology of the College of Physicians and Surgeons, Columbia University

Volume 154, page 37. Insert the following paragraph before Summary and Conclusions: Finally, in connection with a discussion of T-1824 clearance, it is interesting and informative to note the tabulated data of electrophoretic studies on T-1824 and protein in urine of human nephrosis (17). Although it is not stated how dye was measured in nephrotic urine, the T-1824 clearance was 0.37 ml. per minute per square meter of body surface, the albumin clearance was 0.39 while total protein clearance was 0.09. The globulin clearance of 0.03 was very small indeed. Luetscher (17) preferred in 1944 to compare dye with total protein clearance, but since the clearances for T-1824 and serum albumin were nearly equal and considerably greater than that of globulin it is probable that the dye was excreted in the form of dye albumin. In nephrosis, then, the kidney behaves as though injected dye combined selectively with serum albumin leaving vanishingly small amounts of free dye in the blood. On the basis of body surface area a human nephrotic can have a dye clearance 100 times greater than that of a normal dog. This again suggests that dye clearance when analyzed by a sensitive method is a measure of normally occurring albumin clearance.