Renal Blood Flow and Glomerular Filtration

Observations on the renal circulation were carried out as early as 1883, when Cohnheim and Roy1applied the oncometer to this problem. Since then Landergren and Tigerstedt,1using the Ludwig stromuhr, and others,2using modifications of the stromuhr method, have extended the observations on direct measurements of renal blood flow. Van Slyke and his co-workers3contributed an indirect method based on the renal urea extraction ratio and arrived at the conclusion that the urea clearance varied directly as the blood flow. These methods are not applicable to a study of renal blood flow in man. Smith and his associates4developed the diodrast method, an indirect one, applicable to human subjects. Using this method, White5and others6have contributed additional studies. Barbour7and Lazinski8studied circulatory adjustments to hot environmental temperatures, but their work did not include the effect of such temperatures