Sodium and Potassium Content of a Small Artery.

Abstract
Summary The rat tail artery contains more than 5 times as much Na and about half as much K as gastrocnemius muscle. Inulin distribution indicates that cellular and extracellular water phases are about equal in magnitude. Calculation using the inulin space or any other reasonable estimate of water partition shows that much of the Na burden is necessarily cellular and non-ionized.