Studies on the Mode of Action of Diphtheria Toxin VI. Inhibition of Protein Synthesis Induced by Local Infection with Toxinogenic Corynebacterium diphtheriae 1

Abstract

Summary

Protein synthesis in the tissues of guinea pigs after intramuscular challenge with viable, toxinogenic diphtheria bacilli was evaluated by measuring incorporation of ³H–leucine into cellular proteins. Significant inhibition of protein synthesis occurred in muscle tissues (heart, diaphragm, and skeletal muscle) and several non–muscle tissues (kidneys, liver, and adrenal gland). Protein synthesis in the spleen, small intestine, lung and brain was unimpaired. Inhibition of protein synthesis subsequent to intramuscular injection of 10 MLD purified diphtheria toxin was restricted to the three muscle tissues while non–muscle tissues were unaffected. Purified neuraminidase and deoxyribonuclease injected simultaneously with toxin failed to increase the range of tissues inhibited. Possible reasons for the difference in the patterns of inhibition obtained with C. diphtheriae bacilli and purified toxin are considered.