Resting transmembrane potential difference of skeletal muscle in normal subjects and severely ill patients

Abstract

The resting membrane potential difference (Em) of skeletal muscle was measured in 26 normal human subjects, 7 patients with mild illness, and 21 patients with severe, debilitating medical disorders. A closed transcutaneous approach to the muscle was made by needle puncture and the Em was measured utilizing standard Ling electrodes. Measurements revealed an Em of -88 ±-3.8 mv in healthy subjects and -89 ± 2.1 mv in patients hospitalized for minor medical problems. The mean Em in 21 in-hospital patients, judged to be severely ill clinically from a variety of causes, was -66.3 ±9.0 mv. Open deltoid muscle biopsies were performed in 7 of the healthy subjects and in 13 of the severely ill group. Estimation of the intraextracellular water partition was made by calculating the chloride space from the previously measured Em. Analysis of the muscle samples revealed no significant difference in the intra-extracellular potassium ratios of the two groups biopsied. Intracellular Nat concentrations were uniformly increased in the muscle samples of the severely ill subjects and averaged 42.3% higher than those of the normal subjects. The mechanisms which might account for the elevation of intracellular Nat and a depression of Em independent of changes in intraextracellular Ki' ratios are discussed and it is suggested that this defect may be a generalized cellular abnormality which is a common quality of serious illnesses.

Skeletal Muscle Resting Membrane Potential in Potassium Deficiency

“…Muscle fat content was determined by petroleum ether extraction. Partition of intra-and extracellular fluid in the muscle samples was derived from the intracellular chloride concentration of each sample based upon the Em measured for each respective rat (12). Dog experinzents.…”

Muscle cell electrical hyperpolarization and reduced exercise hyperkalemia in physically conditioned dogs.

“…(12)(13)(14)(15). Total muscle water was partitioned into intra-and extracellular compartments based upon distribution of chloride, which is distributed passively in accordance with electrical potential differences (16).…”

Resting Skeletal Muscle Membrane Potential as an Index of Uremic Toxicity

“…The Em became abnormally low on each occasion when dialysis was reduced to 6 h twice weekly (12 h/wk), and returned to normal when dialysis time was increased to 6 (1,2), an abnormally low Em has generally been associated with an elevated cellular concentration of Na (Fig. 6).…”

“…Resting Em was measured directly in the anterior tibial muscle by the same technique reported previously from this laboratory (1,2), except that for this study we employed a Soltec Rinkidinki chart recorder (Soltec Corp., Sun Valley, Calif.) and a Keithly Electrometer (Keithley Instruments, Inc., Cleveland, Ohio) instead of an oscilloscope. This modification substantially improved the ease and reproducibility with which membrane potential could be determined.…”

“…In those individuals whose Em remained normal after 6 wk, dialysis time was reduced further. On thrice-weekly INTRODUCTION Previous studies from this laboratory have shown that the resting transmembrane potential differenice (Em)' of skeletal muscle cells is abnormally low in patients with end-stage renal disease (1,2). In each instance, the low Em was associated with abnormalities of cellular composition, thus suggesting cellular injury.…”