KATP channel deficiency in mouse FDB causes an impairment of energy metabolism during fatigue
| Autor: | Jean-Marc Renaud, Mathieu Paquette, Osama Y. Al-Dirbashi, Nicholas David Calvert, Mary-Ellen Harper, Li Zhen, Maria Benkhalti, Kyle Scott |
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| Rok vydání: | 2015 |
| Předmět: |
0301 basic medicine
medicine.medical_specialty endocrine system Physiology Energy metabolism Biology Oxidative Phosphorylation 03 medical and health sciences chemistry.chemical_compound Mice Adenosine Triphosphate Atp depletion KATP Channels Katp channels Internal medicine medicine Animals Potassium Channels Inwardly Rectifying Muscle Skeletal Glycogen Skeletal muscle Cell Biology Articles Carbon Dioxide Mice Inbred C57BL 030104 developmental biology Endocrinology medicine.anatomical_structure chemistry Muscle Fatigue cardiovascular system Energy Metabolism Glycolysis Muscle Contraction |
| Zdroj: | American journal of physiology. Cell physiology. 311(4) |
| ISSN: | 1522-1563 |
| Popis: | The skeletal muscle ATP-sensitive K+(KATP) channel is crucial in preventing fiber damage and contractile dysfunction, possibly by preventing damaging ATP depletion. The objective of this study was to investigate changes in energy metabolism during fatigue in wild-type and inwardly rectifying K+channel (Kir6.2)-deficient (Kir6.2−/−) flexor digitorum brevis (FDB), a muscle that lacks functional KATPchannels. Fatigue was elicited with one tetanic contraction every second. Decreases in ATP and total adenylate levels were significantly greater in wild-type than Kir6.2−/−FDB during the last 2 min of the fatigue period. Glycogen depletion was greater in Kir6.2−/−FDB for the first 60 s, but not by the end of the fatigue period, while there was no difference in glucose uptake. The total amount of glucosyl units entering glycolysis was the same in wild-type and Kir6.2−/−FDB. During the first 60 s, Kir6.2−/−FDB generated less lactate and more CO2; in the last 120 s, Kir6.2−/−FDB stopped generating CO2and produced more lactate. The ATP generated during fatigue from phosphocreatine, glycolysis (lactate), and oxidative phosphorylation (CO2) was 3.3-fold greater in Kir6.2−/−than wild-type FDB. Because ATP and total adenylate were significantly less in Kir6.2−/−FDB, it is suggested that Kir6.2−/−FDB has a greater energy deficit, despite a greater ATP production, which is further supported by greater glucose uptake and lactate and CO2production in Kir6.2−/−FDB during the recovery period. It is thus concluded that a lack of functional KATPchannels results in an impairment of energy metabolism. |
| Databáze: | OpenAIRE |
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