Nutritional Value for Planarian Worms of Vitamin Depleted Mammalian Tissues.

Abstract

The planarian worm has proved itself a useful instrument for demonstrating changes in the composition of mammalian tissues resulting from changing conditions in the animal as a whole. (Bahrs.) This research was undertaken to ascertain what the planarian worm could reveal as to modification of the nutritional value of tissues derived from animals fed diets with and without the recognized vitamins. Guinea pigs and white rats were used to furnish the tissues. The animals received standard basal diets for a month or more. (For diets used, see Table I.) When definite signs of vitamin A deficiency and polyneuritis were apparent in the respective groups of rats, the planarian worm experiments were started. Guinea pigs showed definite signs of scurvy before their tissues were used in the planarian worm experiments. The guinea pigs maintained upon the vitamin D-free diet, of course, appeared entirely normal when their tissues served for the planarian worm diets. Each group of planarian worms (probably Planaria agilis) consisted of 30 newly regenerated worms, all of the same length. Experimental groups were kept in finger bowls of heat-sterilized river water, and maintained at a constant temperature, 23°C-24°C. The worms were fed twice per week on thoroughly mashed tissues of freshly killed guinea pigs or rats, taken from groups fed the specified vitamin diets. They always ate the tissues well. Spleen, lung, liver, heart and in one case kidney cortex were the tissues used.