Selective inhibitory effect of toxohormone on mice hepatic catalase forms

Abstract

Toxohormone, a factor isolated from tumors by Nakahara and Fukuoka in 1948 [l] and which depresses hepatic catalase activity when injected into mice, has been widely studied. Apart from its effect on hepatic catalase, it also effects the concentration of plasma iron and hepatic ferritin [2]. Toxohormone-like factors with the same biological characteristics have also been isolated from microorganisms with impaired respiration [3] and autolysates of normal yeast [4] and animal tissues [5]. Rampschmidt et al. [6] reported that such effects might be attributed to lipopolysaccharides from bacterial contaminants of raw materials, but there are differences between this and those types of preparations [7,8]. Recently, Urushizaki [8] has found, by means of electrofocussing that they differ markedly in their action on hepatic catalase in rats. Using this technique and following in part to Feinstein and Peraino [9], we have used toxohormonelike factor from ‘petite’ mutants of Saccharomyces cerevisiae to study its effect on the multiple forms of hepatic catalase in mice, specially in relation to its possible site of action.