Richards1 has proved by examinations of the glomerular urine of the frog that urea is filtered through the glomerular loops.
The reabsorption of urea in the tubules was demonstrated by investigations based on the theory of Cushny and of Rehberg.2 Such substances as creatinine are filtered through the glomeruli but are not secreted or reabsorbed in the tubules. With this in mind, one is able to observe the pathway of other substances in the kidney.
The exogenous creatinine clearance method used by Rehberg for the determination of the filtration rate gives reliable results in the dog but not in man (Smith,3 Shannon4). In human subjects administration of creatinine causes an increase in the clearance as a result of secretion. Therefore, the inulin clearance method was employed in the calculation of the filtration rate (Shannon and Smith,5 Richards and his associates6). The endogenous creatinine clearance test probably does not involve this
ARKIN A, POPPER H. UREA REABSORPTION AND RELATION BETWEEN CREATININE AND UREA CLEARANCE IN RENAL DISEASE. Arch Intern Med (Chic). 1940;65(3):627–637. doi:10.1001/archinte.1940.00190090164010
Coronavirus Resource Center
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: