Orotic Acid as One of the Growth-factors of Mice

Abstract

IN 1946 it was shown in our laboratory¹ that orotic acid causes an increase in the reticulocytes in circulating blood, but its action in increasing the body-weight of albino rats by administering orotic acid to animals fed on a basic diet was not made clear. This was attributed to the fact that the basic ration was inadequate. Three years ago we conducted feeding experiments, again with mice instead of rats, and confirmed the growth-promoting action of this acid. This time the experiment was conducted as follows. The basic ration was composed of rice starch 0.6 gm., casein 0.2 gm., lard 0.15 gm., McCollum salt 0.05 gm. Moreover, each animal was given 0.1 gm. of yeast dry powder and two drops of cod liver oil daily. Rice starch was prepared from the polished rice, which was further freed from its embryos by means of hand. Seven litters weighing 7–7.5 gm. born of the same dam were used. Four of them were fed with 5 mgm. of orotic acid daily besides the basic diet; the remaining three were kept on the basic diet only as controls. Until the eleventh day from the beginning of the feeding experiment, no difference between the experimental group and control appeared; but after that increase of body-weight in the latter group ceased or became slowed down considerably, thus contrasting remarkably with that of the experimental group the body-weights of which increased considerably (see accompanying graph).