MITOCHONDRIAL CHANGES INDUCED BY POTASSIUM AND SODIUM IN THE DUODENAL ABSORPTIVE CELL AS STUDIED WITH THE ELECTRON MICROSCOPE BY JULES M. WEISS,* M.D. WITH TECHNICAL ASSISTANCE Or DORIS FLEXSCH

Mitochondrm are important in ion transport, as has been shown in recent biochemical studies. For e~ample, Stanbury and Mudge have shown that isolated mitochondria are capable of maintaining high concentrations of potassium when suspended in potassium poor solutions (7), and Bartley and Davies have shown that isolated mitochondria can take up cations from the surrounding solution against a concentration gradient (1). Mitochondria concentrate the cationic dye Janus green, as is well known from light microscopic observations. That the cationic dye neutral red is also concentrated by mitochondria has been shown by electron microscopic studies (10). This paper reports electron microscopic observations on the effect of sodium and potassium ions upon a cell normally engaged in their transport. The duodenal absorptive cell of the Swiss albino mouse was studied under varying salt and water loads. Mitochondfia were found to develop internal granules when these salts were administered in large amounts.