Simultaneous Use of Il3l-Albumin and Cr51-Labelled Red Cells in Blood Volume Studies in the Goat

Abstract

A method is described using labelled plasma (I131) and red cells (Cr51) simultaneously to determine plasma and red cell volumes. The radioactivity is assayed by counting plasma and cells separately in calibrated hematocrit tubes. I131_albumin alone is used to determine the plasma trapped among packed goat red cells. In vitro and in vivo volumes were determined with goat blood using both labels. The mean trapped plasma among packed goat cells was found to be 19% which is much larger than has been reported for other spp. The hematocrit tube method permits the determination of red cells and plasma volumes as well as hematocrits with small blood samples.