Antitoxin's effect on tetanus toxin induced sphincter pupillae paralysis in the rabbit

Summary The effectiveness of antitoxin in preventing tetanus toxin's blockage of acetylcholine release from the cholinergic nerves of the rabbit iris was tested by injecting purified tetanus toxin into the anterior chamber, and by injecting horse antitoxin at various time intervals either into the anterior chamber, intravenously, or into the anterior chamber and intramuscularly.The results indicate that antitoxin is ineffective in preventing the development of sphincter pupillae paralysis once it is induced by tetanus toxin, prior to appearance of the symptoms.The efficacy of antitoxin treatment depends on the administration of an optimal therapeutic dose.Neither the rate of development, nor the rate of recovery from the maximal pupillary paralysis are altered by antitoxin treatment.The severity, the duration, and the time of complete recovery from the paralysis are directly related to the time antitoxin treatment begins.