The Influence Of Certain Lipids And Proteins On The Effect Of Tetanus Toxin In Mice

Department of Pathology, The University of Queensland, Brisbane, Australia Received December 16, 1969 Accepted March 2, 1970 The effect of a tubercle bacillary lipid, lecithin and some proteins on the activity of tetanus toxin was measured by injecting them into mice with graded doses of the toxin and noting the survival times of the animals. When the tetanus toxin was given as a set volume of a dilution in saline containing lipid or protein, it gave shorter survival times and was lethal at lower concentrations than when it was given as the same dilution in saline alone. However, the addition of lipid or protein to the toxin already diluted in saline alone had no influence on the survival times of the mice. Injection of the corresponding amount of toxin as a measured volume of the initial dilution gave even shorter survival times. Tetanus toxin is adsorbed or inactivated at glass surfaces and is inactivated at gas-liquid interfaces. The losses from these causes are reduced in the presence of lipid or protein in the diluent or by treating the glass surfaces with these materials before they are brought into contact with diluted toxin. The apparent activity of the lipids or proteins in activating the toxin is due to the reduction of such losses. No evidence was found of any direct effect on the activity of the toxin.