Inhibition of Growth of Rat by Oral Administration of Methyl-cholanthrene. Effects of Dietary Cystine and Methionine Supplements.

Abstract

In the present communication it is desired to report preliminary results obtained in studies of the effects of certain carcinogenic substances on sulfur metabolism. The experimental approach employed in the first series of investigations is similar to that which has resulted in the demonstration that bromobenzene,1 cholic acid,2 naphthalene,3 and iodoacetic acid4 exert an inhibiting effect on the growth of the young white rat when any one of these compounds is incorporated into a basal diet of relatively low protein content. The addition of either 1-cystine or dl-methionine to the basal diet containing either bromobenzene, cholic acid, naphthalene, or iodoacetic acid resulted in a prompt stimulation of growth, despite the continued presence of the foreign organic compound in the diet. It was suggested that these organic substances are capable of producing a specific deficiency in the sulfur-containing amino acids, probably through the requirements of the organism for organic sulfur, in the form of cystine...