Experimental sodium chloride deficiency in man

Dehydration plays an important part in the pathology of a number of diseases. The loss of water may take place through the kidney (as it does in diabetic coma), the gut (as in pyloric stenosis, paralytic ileus, acute diarrhoea, and vomiting or cholera), the lungs and skin (as in hot dry atmospheres) or occasionally through other channels. This loss of water has been known for a very long time to be associated with loss of salt, but a study of the literature reveals considerable confusion of thought as to the relationship of one to the other. This is particularly well illustrated by the discussions of some of the experimental work on Addison’s disease. Much experimental work has been done on the lower animals to elucidate the pathology of the intestinal obstructions; diabetic coma has been studied to some extent, and in the last 5 years Addison’s disease has been produced and controlled experimentally in numerous rats, cats, and dogs. In every case, however, the salt or water deficiency is but a part of the picture. From the acute and dangerous nature of the human diseases and the complications they introduce it is particularly difficult to study the effects of severe water or salt deficiency in patients. Some work has been carried out on diabetic coma, which, however, presents water and salt loss in its most complicated form. No papers of any value have been found on severe uncomplicated salt deficiency. It was therefore decided to make a direct experimental attack on the question and normal human adults were selected as the most suitable subjects. The deficiency was produced by a salt free diet combined with sweating. Nature and Arrangement of the Experiments ( a ) The Subjects —One of the women students of this Hospital volunteered to be the subject for the first experiment, which was of a semi-quantitative nature and was intended to try out methods rather than get results. Mild deficiency only was produced because E. ceased to lose significant amounts of NaCl in her sweat after 4 or 5 days. Nevertheless, some interesting observations were made which will be discussed in their appropriate place, and the fact that this subject reacted to the experimental regime so differently from the others is a matter which may be of some importance and will be further investigated. The second and third experiments were done on two males, R. A. M. age 36, and R. B. N. age 24. In both experiments every reasonable precaution was taken to make the whole investigation as quantitative as possible. Both subjects were in good health when the experiments began and the observations were not upset by any “colds” or other minor pathological interferences. R. A. M. is normally an active man, fond of exercise, and gets enough of it throughout the year to keep himself physically fit. R. B. N. is a South African, who came to this country with a Rhodes Scholarship and is now a medical student. He takes enough regular exercise to keep in fair training.