The Effect of Nutritional Regimes Upon Collagen Concentration and Survival of Rats

Abstract

It is generally believed that food restriction of experimental animals in the adult age does not alter the expected lifespan of the animals. Already the early experiments of McCay and coworkers (1) showed th_at no further increase in the lifespan could be brought about by restricting the food intake in adult animals, namely in rats beyond one year of age. Some other data on the same topics were published by Barrows and Roeder (2) who reported that rats that were subjected to limited food intake in the adult age did not survive longer than their ad libitum fed counterparts. Similar effects were observed also in insects. So for instance Kopeć (3) was unable to prove the increase in the lifespan of the imago of Drosophila if the imagos were subjected to reduced dietary intake. In connection with this latter experiment Northrop (4) proved that the overall increase in lifespan of Drosophila can be accounted for by the changes which occur during the larval stage. In a series of more recent experiments Barrows (5) studied the overall lifespan of some rotifers using different types of restricted diet. This author observed that in some cases animals which were food restricted throughout their whole lifespan lived shorter than those which were kept on a food restricted regime after cessation of, egg production.