Effect of levamisole and litoralon on amphibian metamorphosis

Abstract 1. Previous investigations revealed vitamin A-like lysosomal activation, as well as facilitation of amphibian metamorphosis and tail involution caused by litoralon (gamma-L-glutamyl-taurine), a substance increasing immune surveillance. 2. Present studies have shown that levamisole exerts an effect on the metamorphosis of Rana arvalis Wolterstorffi in many respects similar to that of vitamin A and litoralon, i.e. it accelerates lysis of the tail, transformation of the gut and development of goblet cells of the intestinal mucosa. 3. Levamisole in higher doses is teratogenic in the tadpole, like vitamin A. 4. It is suggested that the favourable effect of levamisole in immune-anergic conditions is due, at least partly, to its vitamin A-like direct or indirect lysosomal labilizing property.