Measurement of Intracellular pH of Skeletal Muscle with pH-sensitive Glass Microelectrodes*

Abstract

Summary. We used three methods to examine the relationship among intracellular pH, transmembrane potential, and extracellular pH. Singlebarreled electrodes permitted the determination of resting potential and intracellular pH with a minimum of cellular injury. Double-barreled electrodes, which incorporated a reference as well as a pH-sensitive electrode in a single tip, facilitated the direct measurement of intracellular pH without the interposition of the transmembrane potential. Triple-barreled electrodes permitted measurement of intracellular pH during the controlled hyperpolarization or depolarization of the cell membrane.The results of all three methods were in close agreement and disclosed that the H+ activity of intracellular and extracellular fluid is in electrochemical equilibrium at any given transmembrane potential. This implies that the determinants of intracellular pH are the transmembrane potential and the blood pH. The actual pH of the normal resting muscle cell is 5.99, as estimated from the normal transmembrane potential and blood pH, or as determined by direct measurements of intracellular pH.

Association of Glyceraldehyde‐3‐Phosphate Dehydrogenase with the Particulate Fraction of Chicken Skeletal Muscle

“…Waddell and Bates [36] in their review on intracellular pH reported a value of 6.61 -7.06 for human skeletal muscle and 6.84-7.09 for dog skeletal muscle. Carter et al [37] using glass microelectrodes, found a value of 6.0 for the intracellular pH of skeletal muscle. More recently, Roos [38] reported the intracellular pH of rat muscle to be 6.…”

Rate of disappearance of labeled carbon dioxide from the lungs of humans during breath holding: a method for studying the dynamics of pulmonary CO2 exchange

“…Intracellular electrodes, indicators, and the dissociation of weak bases and acids (39)(40)(41) have all been used to measure intracellular pH. In this study the lung pH was measured by the third technique using the bicarbonate and carbonic acid system.…”

Skeletal Muscle Resting Membrane Potential in Potassium Deficiency

“…Control animals received similar amounts of electrolyte-deficient diet to which had been added 1 meq of potassium chloride and 2 meq of sodium choride. At the end of 10 days, both groups of rats were anesthetized with sodium pentobarbital and muscle Em was measured by methods described previously (11). After the measurement of muscle Em, aortic blood was taken for measurement of serum electrolyte concentration, and a generous portion of anterior thigh muscle was sampled for analysis of water, sodium, potassium, and chloride.…”