[Skip to Content]
[Skip to Content Landing]
August 5, 1933


JAMA. 1933;101(6):451. doi:10.1001/jama.1933.02740310035014

The various theories proposed to account for the production of urine by the kidney involve combinations of the following factors: glomerular filtration, glomerular secretion, absorption in the tubules and secretion by the tubular epithelium. Efforts to obtain experimental evidence in support of one or the other of the theories have been limited by the extremely small size of the unit of structure involved, the glomerulus and the associated tubule. It is obvious that a simultaneous comparison of the chemical composition of the blood in the renal vessels and of bladder urine will yield little cogent information concerning glomerular function and hence the process whereby the urine is actually formed. Of particular interest, therefore, are the recent reports of Richards and his co-workers1 in which the earlier studies of the collection and chemical analysis of glomerular urine have been confirmed and extended. This further series of investigations seemed necessary, because