BINDING OF D-TUBOCURARINE DI[METHYL-C-14] ETHER IODIDE AND OTHER AMINES TO CARTILAGE, CHONDROITIN SULFATE AND HUMAN PLASMA-PROTEINS

  • 1 January 1975
    • journal article
    • research article
    • Vol. 195  (2) , 242-250
Abstract
The binding of d-tubocurarine di [methyl-14C] ether iodide (d-TCE) and other amines to bovine nasal septum, chondroitin sulfate (CS) and human plasma proteins was examined by equilibrium dialysis. Bovine nasal septum and CS bound d-TCE to a greater extent than they did morphine, d-methadone (d-ME) and l-methadone (l-ME). Cartilage, relative to an equal weight of pure CS, bound slightly more d-TCE, 50% more d-ME and l-ME, and the same amount of morphine. The amount of d-TCE bound to pure CS was similar to that of decamethonium [methyl-14C] dibromide but less than that of 2 new iodinated bisquaternary compounds: 1,6-bis(N,N-dimethyl-3-iodobenzylamino)hexane dichloride and 1,6-bis[dimethyl-(3-amino-4,6-diiodobenzyl)amino]hexane dichloride. The binding of d-TCE is greater for pure CS than for impure CS which contains 26% protein, and binding to either preparation was inversely related to Na+ concentration. In the drug concentration range explored, 30 to 40% of d-TCE is bound to plasma proteins, which is twice that of decamethonium binding but equivalent to the binding of morphine and about 1/2 the binding of d-ME and l-ME. In this same drug concentration range, each gram of cartilage (dry weight) can bind about 10-7 mol of d-TCE. The binding of d-TCE to cartilage is probably an ionic type bonding to the anionic sites of the ester sulfates and glucuronate moieties of CS, and the binding of d-TCE to the protein fraction of cartilage is probably equal to, or less than, its binding to the CS fraction. Cartilage may represent a measurable distribution pool for d-tubocurarine.