Adsorption of tetanus toxin by brain tissue

Abstract

The potency of tetanus toxin as measured by combining power is markedly reduced by mixing with fresh or dried preparations of rabbit brain, and by dried horse brain. A number of other bacterial toxins are not so affected. Tissues other than brain were not found to have this specific effect. The state of division of the tissue, the time over which adsorption takes place, and the relative proportions of adsorbate and adsorbent affect the quantity of toxin removed. When the quantity of adsorbent and the volume of adsorbate are constant, the quantity of toxin removed per gram of adsorbent is proportional to the equilibrium concentration of the toxin, but not directly so. Some of the tetanus toxin adsorbed onto fresh or dried preparations of brain tissue can be recovered by washing with physiological saline. Brain toxin mixtures, when treated with tetanus antitoxin, neutralized an amount of antitoxin about equivalent to the toxin retained by the tissue. Successive adsorption of tetanus toxin by brain tissue leads to an alteration in the ratio L + per ml./Lf per ml. of the toxin. The adsorption capacity of brain tissue may be reduced by first washing with tetanus toxoid or heated toxoid or with diphtheria toxoid.