Further Evidence of Insusceptibility of the Rat to a Dietary Deficiency of Vitamin C

Abstract

Svirbely 1 has reported that the adrenal gland and liver tissues of rats and mice, reared for several generations on a diet devoid of vitamin C, were rich in the anti-scorbutic substance. As far as one can ascertain from the literature, the vitamin C requirement of the rat had been investigated chiefly from the standpoint of growth and fertility, since the characteristic scorbutic lesions such as osteoporosis, sub-periosteal hemorrhages, and petechiae of cutaneous and mucous surfaces had not been observed in this species. 2 Moreover, such observations had not been extended, as a rule, to more than one generation. Therefore in order to obtain further evidence that the rat requires no dietary supplement of vitamin C, the incisors of animals maintained and reared for 3 generations on scorbutic diet were examined histologically according to the method of Höjer, 3 as one of the most specific and sensitive criteria of the scorbutic process.

A small series of 6 female and 7 male rats was placed on a diet of boiled whole milk and dried bread. This diet, tested on guinea pigs, was found to be scorbutic; but in other respects complete and adequate. The substitution of fresh whole milk not only prevented and cured scurvy, but maintained guinea pigs in good health. After 6 months of this regime the group was bred, and the offspring in turn raised and bred on the C-deficient diet. Of the 3 generations so obtained, the lower incisors were examined histologically for evidence of scurvy. The average ages of the f₀, f₁, f₂ groups were respectively 12 to 15, 5 1/2, and 2 months. In no instance did the sections show any deviations from the normal tooth structure.