Amyotrophic lateral sclerosis (ALS) is the most common fatal motor neuron disease in adults. Numerous studies indicate that ALS is a systemic disease that affects whole body physiology and metabolic homeostasis. Using a mouse model of the disease (SOD1(G86R)), we investigated muscle physiology and motor behavior with respect to muscle metabolic capacity. We found that at 65 days of age, an age ...

The heart adapts to changes in nutritional status and energy demands by adjusting its relative metabolism of carbohydrates and fatty acids. Loss of this metabolic flexibility such as occurs in diabetes mellitus is associated with cardiovascular disease and heart failure. To study the long-term consequences of impaired metabolic flexibility, we have generated mice that overexpress pyruvate dehyd...

Escherichia coli NZN111, which lacks activities for pyruvate-formate lyase and lactate dehydrogenase, and AFP111, a derivative which contains an additional mutation in ptsG (a gene encoding an enzyme of the glucose phophotransferase system), accumulate significant levels of succinic acid (succinate) under anaerobic conditions. Plasmid pTrc99A-pyc, which expresses the Rhizobium etli pyruvate car...

Seven untrained volunteers [3 men, 4 women, 20.1 +/- 2.0 (SD) yr, 66. 0 +/- 11.0 kg, 171 +/- 13 cm] participated in a 10-day cycle exercise training program. Resting muscle samples were obtained from vastus lateralis before and after 5 and 10 days of training. Mitochondrial ATP production rate (MAPR) was assayed in isolated mitochondria by using a bioluminescence technique and referenced to the...

Combining endurance and strength training (concurrent training) may change the adaptation compared with single mode training. However, the site of interaction and the mechanisms are unclear. We have investigated the hypothesis that molecular signaling of mitochondrial biogenesis after endurance exercise is impaired by resistance exercise. Ten healthy subjects performed either only endurance exe...

Pyruvate dehydrogenase (PDH) plays an important role in regulating carbohydrate metabolism in skeletal muscle. PDH is activated by PDH phosphatase (PDP) and deactivated by PDH kinase (PDK). Obesity has a large negative impact on skeletal muscle carbohydrate metabolism, whereas endurance training has been shown to improve regulatory control of skeletal muscle carbohydrate metabolism, more so whe...

Metabolic flexibility is the capacity of a system to adjust fuel (primarily glucose and fatty acids) oxidation based on nutrient availability. The ability to alter substrate oxidation in response to nutritional state depends on the genetically influenced balance between oxidation and storage capacities. Competition between fatty acids and glucose for oxidation occurs at the level of the pyruvat...

This study evaluated the link between swimming endurance and condition of Atlantic cod Gadus morhua that had been fed or starved during the 16 weeks preceding the tests, and assessed whether muscle metabolic capacities explain such links. The condition factor [(somatic mass x fork length(-3))x100] of starved cod was 0.54+/-0.1 whereas that of fed cod was 0.81+/-0.1. In white and red muscle, we ...