Tissue Buffering in Rat Diaphragm

¹ From the Department of Physiology, The University of Rochester School of Medicine and Dentistry, Rochester, New York

Excised rat diaphragm muscles were incubated in nutrient media at various hydrogen ion concentrations. Those in the more acid media lost more potassium and more sodium than their controls at ph 7.4, and the extent of the loss was increased by further depression of the ph. The potassium loss was unaccompanied by either chloride or phosphate, nor was there any difference in the weight change or inulin space between the control and experimental muscles. These results are consistent with the theory that intracellular cation exchanges for excess extracellular hydrogen ion.