Measurement of regional blood flow with sulfanilamide (4-amino benzene sulfonamide)

Abstract
A new technique utilising sulfanilamide (4-amino benzene sulfonamide) as a diffusible indicator is described for the measurement of organ blood flows in the rat. After a bolus injection the indicator is rapidly distributed in the tissue water and in most organs its tissue-blood partition coefficient corresponds to the relative water content of the organ. Sulfanilamide is, however, rapidly secreted by the renal tubules and slowly acetylated in the liver. This difficulty can be eliminated by the introduction of appropriate partition coefficients. The organ blood flows estimated with sulfanilamide were in the same animals compared with flows obtained by the86Rbuptake and by the radioactive microsphere techniques, and a high correlation was found between the flow values obtained by the different methods [sulfanilamide-86Rb:r = 0.992; sulfanilamide-MS:r = 0.995]. The merits and disadvantages of the individual methods are discussed.