THE BINDING OF d-TUBOCURARINE CHLORIDE TO PLASMA PROTEINS

¹ Departments of Anesthesiology, Pharmacology and Clinical Biochemistry, Hadassah University Hospital and the Hebrew University-Hadassah Medical School, Jerusalem, Israel

Plasma levels of d-tubocurarine chloride were determined in nine patients, who received identical doses of the drug. Exceptionally high plasma levels of the drug were found in two patients refractory to the relaxant.

Paper electrophoresis of plasma to which DT was added in vitro showed that in refractory plasma the major part of DT moved with the albumin fraction, while in normal plasma the major part remained with the gamma-globulin. The electrophoretic mobility of the albumin was not altered by the addition of DT.

Dialysis experiments showed that both albumin and gamma-globulin are able to bind considerable quantities of DT.

Dogs in whom curarization was effected by intravenous injection of DT in 0.9 per cent NaCl did not respond to the same dose of DT after preincubation with albumin. Curarization was effected only after the amount of DT injected relative to albumin was greatly increased.