STUDIES ON THE PLASMA PROTEINS. V. THE EFFECT OF CONCENTRATED SOLUTIONS OF HUMAN AND BOVINE SERUM ALBUMIN ON BLOOD VOLUME AFTER ACUTE BLOOD LOSS IN MAN1

Abstract

To test the effectiveness of concentrated solns. of serum albumin in drawing fluid into the circulation, large venesections were performed on normal human subjects, and immediately thereafter solns. of serum albumin of approx. 25% conc. were injected intravenously. Changes in blood vol. were measured by means of detn. of the plasma vol. (Evans blue dye method), venous Hb, serum protein, and hemato-crit readings. The plasma vol. was detd. before venesection and 1, 20, and 72 hrs. after venesection. The plasma vol. after bleeding was detd. by subtracting the plasma removed (calculated from measurement of total blood removed and hematocrit reading) from the initial plasma vol. Two control expts. were performed, one to test the response to venesection without treatment and the other to test the response to an inj. of reconstituted dried human plasma. Five subjects received concentrated human albumin and 6 subjects concentrated crystallized bovine albumin. The expts. were devised to compare the response to each type of albumin and the response to concentrated albumin with the subjects both mildly dehydrated and in a state of artificial hydration as a result of a high intake of salt and fluids. Regardless of the state of hydration of the subject, the inj. of concentrated albumin after a venesection produced a very prompt increase in plasma vol., considerably exceeding the vol. of albumin soln. injected, thus indicating that fluid had been drawn into the circulation. Although the values obtained varied considerably, the avg. amt. of fluid added to the plasma by each g. of albumin was 17.4 ml., which corresponded fairly closely to the 18 ml. expected from in vitro measurements of the osmotic pressure of serum albumin. No significant differences were observed between the responses to albumins of human and bovine origin. Although the state of hydration made little difference in the immediate response to albumin, if dehydration were continued, mild hemoconc. subsequently occurred as it would in any normal subject. The subjects were carefully studied over a 3-mo. period for evidence of harmful effects and none was found. The authors point out that, although these expts. demonstrate that bovine albumin functions as effectively as human albumin in increasing colloid osmotic pressure, much more extensive studies are necessary to test its safety for therapeutic use in man.