Splenic Red Cell Sequestration and Blood Volume Measurements in Conscious Pigs

摘要

When estimated by the dilution of Cr-labeled red blood cells under nearly basal conditions, immature splenectomized pigs (n = 20) had a circulating red cell volume of 17.8 + or - 1.64 (SD) ml/kg. At an assumed body-to-large vessel hematocrit (BH:LH) ratio of 0.9, plasma volume was 49.6 + or - 3.12 ml/kg and blood volume 67.3 + or - 3.67 ml/kg. Sham-operated pigs (n = 20) had a irculating red cell volume of 16.2 + or - 1.39 ml/kg, and blood volume of 67.2 + or - 4.12 ml/kg. Kinetic analysis of early Cr loss from circulating blood of the sham-operated pigs indicated a splenic red cell sequestration of 4.5 + or - 0.89 ml/kg and t1/2 of 9.76 + or - 1.93 min for splenic red cell turnover. Epinephrine injection (n = 6) and physical restraint (n = 8) caused rapid mobilization of splenic red blood cells in sham-operated pigs. Volume estimates in splenectomized pigs (n = 7) based on simultaneous dilutions of Cr-labeled red blood cells and I-labeled bovine albumin gave circulating red cell, plasma, and blood volumes. (Reprints)