Effect of Starvation on Healing of Rickets in Rats.

Abstract

McCollum and his coworkers 1 demonstrated in 1922, that fastingwould cause active rickets to heal within 24 or 48 hours. The immediate cause of such healing seemed clear when it was demonstrated by Kramer and Howland 2 and confirmed by Cavins 3 that starvation was promptly followed by a rise in the inorganic phosphorus of the blood serum.

Some experiments which we have performed recently seem to cast doubt upon this belief, and would seem to suggest that starvation causes healing by some other means than raising the blood phosphorus.

In the course of some experiments∗ on the effect of salts on calcification in vitro, we ran a duplicate series with preparations made from rachitic rats which had been starved for 24 hours before use. The results which are shown in the accompanying table were quite different from those obtained on the control series of rachitic rats which had not been starved.

The solution to which 51.3 mM. NaCl had been added inhibited calcification entirely with preparations made from rats kept on the McCollum No. 3143 diet, while the preparations made from the starved rats calcified perfectly.

Obviously the amount of blood clinging to a sample of sliced cartilage is negligible, and the result must therefore be attributed to some other change brought about in the cartilage by starvation.