Water and Electrolyte Distribution in Cardiac Muscle

Abstract

Electrolyte analyses are presented on cardiac muscle and serum from cats which were subject to adrenal deficiency, excess adrenal corticoids, salt deprivation, excess salt, peri-nephrectomy or various combinations of the above. Water, Na and K distribution have been derived according to a modified Conway hypothesis. Intracellular concn. of Na decreased in adrenal deficiency and in salt depletion; it increased following excessive adrenal hormones or salt admn. and during perinephritis. Changes in intracellular K were in the opposite direction. Two conclusions suggested by the present data are discussed: that water does not move freely to maintain iso-osmolarity; and that the extracellular fluid volume increases more than intracellular fluid volume during adrenal insufficiency.