Successive determination of blood volume of normal human subjects using low doses of I-131-HSA and P32-RBC.

The determination of blood \'olume of a group of normal adult subjects, including both men and women, has been carried out using low doses of Jl31_ labelled human serum albumin, about O.O? jlc per kg of body weight. Further, a successive test was carried out using small doses of p32-tagged red blood cells, about 0.01 jlc per kg of body weight. These doses are at least 10 times less than the normally used tracer doses for such purpose. Some of the cases were again subjected for the estimation of blood volume by a conventional tot.al dose of20 jlc of Il3l-HSA and also T-1824 dye. In the present study an anticoincidence gas-flow counter has been utilised for the assay of the radioactivity which has helped to carry out the experiments with the reduced doses of isotopes.