Table 2.
In vitro effects of normal and low external K+ concentrations on lactate release from skeletal muscle of normokalemic rats
| Muscle type | Lactate release (μg l−1 mg−1) 5 K+ | Lactate release (μg l−1 mg−1) 0.5 K+ |
|---|---|---|
| Tibialis anterioris (17) | 15.31±4.1 | 23.47±3.5* |
| Extensor digitorum longus (8) | 17.66±8.3 | 29.02±8* |
| Flexor digitorum brevis (9) | 21.26±6.8 | 54.71±6.3* |
| Soleus (4) | 29.08±9.3 | 27.8±5.1 |
Lactate release was evaluated in vitro under aerobic conditions, at 35 °C, by spectrophotometric determination. Lactate release (μg l−1 mg−1) (5 K+) represents data from muscles incubated for 2 h in normal Ringer solution containing 5 mM K+. Lactate release (μg l−1 mg−1) (0.5 K+) represents data from contralateral muscles from the same rats incubated for 1 h with low-K+ solution containing 0.5 mM K+, followed by 1 h incubation in normal Ringer solution. The numbers in the brackets represent the number of rats.
*
Significantly different from the data of contralateral muscles (P<0.05).