Effect of electrical stimulation on total contents of Na+ and K+ in rat EDL muscle in vivo
| Experimental conditions | Total K+ content | Total Na+ content |
| µmol/g wet wt | µmol/g wet wt | |
| Resting muscles | 98.2 ± 2.2 (8) | 13.5 ± 1.0 (8) |
| 5-Hz stimulation, 300 s | 85.6 ± 3.3 (8)a | 21.7 ± 1.0 (8)b |
| Resting muscles | 90.8 ± 1.9 (6) | 10.7 ± 0.5 (6) |
| 60-Hz stimulation, 60 s | 77.7 ± 1.8 (7)b | 17.1 ± 0.5 (7)b |
| Experimental conditions | Total K+ content | Total Na+ content |
| µmol/g wet wt | µmol/g wet wt | |
| Resting muscles | 98.2 ± 2.2 (8) | 13.5 ± 1.0 (8) |
| 5-Hz stimulation, 300 s | 85.6 ± 3.3 (8)a | 21.7 ± 1.0 (8)b |
| Resting muscles | 90.8 ± 1.9 (6) | 10.7 ± 0.5 (6) |
| 60-Hz stimulation, 60 s | 77.7 ± 1.8 (7)b | 17.1 ± 0.5 (7)b |
As described in Materials and methods, rats were anaesthetized and the EDL muscles stimulated at resting length using platinum wire electrodes and 1-ms pulses at 10 V applied at the durations and frequencies indicated. After stimulation, the muscles were immediately washed four times for 15 min in ice-cold Na+-free Tris-sucrose buffer, blotted, weighed, and taken for flame photometric determination of Na+ and K+ content. Values are given as mean ± SEM, with the number of muscles in parentheses.
P < 0.007 compared with resting muscles.
P < 0.001 compared with resting muscles.