CIRCULATING RED CELL VOLUME MEASURED SIMULTANEOUSLY BY THE RADIOACTIVE IRON AND DYE METHODS 1

Abstract

Circulating red cell vol. was detd. by both the radioactive Fe and dye-plasma methods in 40 normal [male][male] and 40 normal (stray) dogs. The ratio of the radio-Fe to the dye-plasma red cell vol. averaged 0.85 in humans and 0.82 in dogs. The ratio of avg. body hematocrit to large vessel hematocrit averaged 0.91 in both series. There is no relationship of either ratio to absolute plasma vol. or large vessel hematocrit. There is a linear relationship of body hematocrit to large vessel hematocrit. The probability that the hematocrit of minute vessel blood is less than the body hematocrit is discussed.