Chloremia

CHLOREMIA, the content of chlorides in the blood. Normal human blood contains about 0.35% chlorine. It is customary to express the chloride content in terms of NaCl, since the bulk of the chlorine present in the blood is in combination with Na. The amount of chlorides in the blood, expressed as NaCl, is 0.56–0.6%. Chlorides are located predominantly in the liquid part of the blood. Among the formed elements of the blood, the largest amount of chlorides is found in erythrocytes (see Blood, mineral substances, chlorine). The most important role of chlorides in the organism reduces to maintaining the osmotic pressure of the blood and tissues. Regarding physiological significance, see Metabolism, mineral, Ions. Under various pathological conditions, the blood chloride content changes. Thus, with profuse vomiting and diarrhea leading to a loss of chlorides by the organism, their content in the blood decreases. In nephrosis, a decrease in blood chloride content is more often observed, although in individual cases a normal content takes place, and in rare cases even an increased one. In diabetes insipidus, on the contrary, in most cases the chloride content after at least a short-term abstention from water intake turns out to be increased (hyperchloremic-hypochloruric form according to Veil) and only in a small number of cases does the chlorine content in diabetes insipidus turn out to be reduced (hypochloremic-hyperchloruric form according to Veil). The introduction of significant doses of NaCl into the organism both per os and intravenously leads only to a short-term increase in blood chloride content. The kidneys have the same importance for the regulation of NaCl concentration as for the regulation of [H]. When significant amounts of NaCl are introduced, its retention in the organism takes place. The place where it can accumulate in the organism in significant quantities is primarily the skin and connective tissue. In the absence of chlorides in food, the kidneys persistently retain the reserve of chlorides present in the organism, and their removal from the organism through salt starvation presents great difficulties. A number of clinicians note a connection between the content of chlorides and residual nitrogen in the blood. A number of cases have been described in which a decrease in the NaCl content in the blood was accompanied by an increase in its residual nitrogen (RN). This so-called chloropenic azotemia is observed in the absence of independent kidney damage and differs from true azotemia in that the urine as a rule remains concentrated, and leukopenia is noted in the blood, corresponding to the intensity of chloropenia and disappearing together with it upon rational therapy. Of great practical importance is the disturbance of chloride metabolism in diseases of the gastrointestinal tract and first of all the stomach. Based on recent work, it can be thought that general weakness and dyspeptic phenomena in such patients, up to and including nausea and vomiting, are connected with the reduced chlorine content in the blood. A salt-free diet, so widely prescribed in the treatment of edematous conditions and certain kidney disorders, if carried out for a long time, can lead to the development of the chloropenia symptom complex. It is interesting to note that the introduction of bromine salts leads to an increased excretion of chlorides, and part of the chlorides in the blood turns out to be replaced by bromides. By such displacement of chlorine, it is possible to achieve a reduction of its content in the blood of a rabbit to one-third of the normal concentration.