Intake and Excretion of Chloride

Abstract

Cl is a main anion of the extracellular fluid with little inside the cells; intracellular anion is mostly provided by protein and organic phosphate and cannot diffuse into extracellular fluid. In the simplified model of tissue fluids (p. 300), Cl concentration in the interstitial fluid is regarded as that of plasma, corrected for the Donnan factor due to the difference in protein concentration between plasma and interstitial fluid. Cl in the body, estimated by exchange with Br, is approximately 31 mmol/kg body weight in man and 33 mmol/kg in dogs and this is almost equal to body Cl estimated by carcass analysis. Of this about 50% is in plasma, interstitial fluid and lymph, about 17% attached to dense connective tissue and cartilage, 15% in bone and about 12% is intracellular (Edelman and Liebman, 1959).