Pseudocholinesterase activity of human whole blood, bank blood, and blood protein solutions.

Pseudocholinesterase (E.C. 3.1.1.8) activity was measured in plasma of whole blood, bank blood, and several commercially available blood protein solutions by means of a colorimetric assay technique at 25 degrees C, pH 7.7, and with butyrylthiocholine as substrate (Merckotest-R No. 3337). Activity of whole blood was 5.79 plus or minus 0.20 U x ml-1, of bank blood 4.53 plus or minus 0.27 U x ml-1, and of two human serum solutions (Biseko-R, Seretin-R) 3.05 plus or minus 0.13 and 3.04 plus or minus 0.22 U x ml-1, respectively (mean plus or minus S.E.M.). The other blood protein solutions contained no clinically significant esterase activity. Since transfusion of blood plasma has been suggested for treatment of cholinesterase deficiency and postoperative suxamethonium-induced muscle paralysis, an in-vitro attempt was carried out to correlate the amount of plasma necessary and the rise of pseudocholinesterase activity in the recipient's blood: A large amount of blood has to be transfused to yield a comparatively small increase in esterase activity. Thus, considering the potential hazards of blood transfusion, this treatment does not seem to be advisable.