Abstract
We examined the expression of the monocarboxylate transporters in rat skeletal muscles. All skeletal muscles examined co-expressed MCT1 and MCT3. While MCT1 was highly correlated with the oxidative indices of rat skeletal muscles (muscle oxidative fiber composition, citrate synthase activity, and LDH-1). MCT3 was not correlated with these indices of the muscles oxidative capacities. MCT3 content in fast-twitch glycolytic and fast-twitch oxidative glycolytic rat hindlimb muscles were similar while MCT3 content of the slow-twitch oxidative muscle was markedly lower than in these other muscles. With 7 days of chronic electrical stimulation (10 Hz, 24 h/day) via the peroneal nerve, there was a 1.5 to 1.9 fold increase in MCT1 content of the chronically stimulated muscles (i.e. extensor digitorum longus (EDL), the red (RTA) and white tibialis anterior (WTA)). In contrast, no changes were observed in the MCT3 content of these 7 day, chronically stimulated muscles. Thus, the observed increase in lactate uptake by chronically stimulated muscles can be ascribed to increases in MCT1 (r=0.96) since no changes were observed in MCT3. Clearly, the expression of MCT1 and MCT3 are regulated differently.
| Original language | English |
|---|---|
| Pages (from-to) | A1027 |
| Journal | FASEB Journal |
| Volume | 12 |
| Issue number | 5 |
| Publication status | Published - 20 Mar 1998 |