DIETARY CHLORIDE DEFICIENCY AND ALKALOSIS IN THE RAT

Abstract

Signal advances in the knowledge of the biochemical functions of the different mineral elements have been made in recent years through studies of the effects of diets deficient only in a single element upon the animal organism .With certain of the mineral elements normally present in great abundance in the diet, notably potassium (l-3) and sodium (d-6), the degree of dietary deficiency must be very severe to bring out the characteristic effects of their deprivation.Few experiments have been carried out on the effect of chloride deficiency and these have heretofore yielded little indication of a striking need for chloride by the animal organism.In experiments by Osborne and Mendel ( 7) and by St. John ( 8) there was no decrease in the growth of rats when the chloride content of the diet was reduced to 0.035 and 0.05 per cent respectively.Orent-Keiles, Robinson, and McCollum (5) noted retardation of growth on a low chloride diet of unknown chloride content and Marquis (9) on a diet of 0.01 per cent chloride.In a paper which appeared when the present work was nearly completed, Voris and Thacker (10) found that a diet containing 0.02 per cent chloride caused a depression of appetite, increased consumption of water, increased heat production, and diminished body gain of nitrogen and energy as well as retarded growth.The present study was prompted by the knowledge that recent advances in scientific knowledge and technology of the nutritionally essential factors allow the preparation from purified constituents of diets drastically low in chloride, or any other desired component, but apparently adequate otherwise for the biological needs of the rat.One reason for undertaking the investigation was that from the well known reciprocal relationship between the chloride and bicarbonate concentrations in the blood (11) it can be predicted that a continuous chloride deficiency should produce a chronic state of alkalosis in the animal.Virtually all of the available information on alkalosis has been gained from acute experimental conditions and the study of chronic alkalosis may be expected to yield interesting information on the adaptation of the animal organism to this and its associated state, tetany.This paper contains the report of the effects of a diet containing 0.012 per