Comparison of total body and tissue losses of sodium and chloride with losses from sucrose space in salt-depleted rats

Abstract

When about 30% of total body Na and Cl is removed from normal adult rats by intraperitoneal dialysis, the external loss of Na and Cl measured 24 hours later is adequately accounted for by loss from ECF (sucrose space). Only small amounts of Na and Cl enter ECF from gastrointestinal contents and bone. Conclusions drawn from muscle and skin samples agree with that from whole body. Such depleted animals remain almost in water balance. Evidence is presented that sucrose space is an equally valid measure of ECF in normal and in depleted animals.