Glycogen synthesis from lactate in skeletal muscle of the lizard Dipsosaurus dorsalis.

摘要: The capacity of skeletal muscle to synthesize glycogen from lactate was tested in the iliofibularis desert iguana, Dipsosaurus dorsalis. Like other reptiles, accumulates significant lactic acid concentrations following vigorous exercise. After 5 min progressively faster treadmill running at 35 degrees C (final speed = 2.2 km/h), blood concentration increased over 14 mM, which decreased 11 mM after 2 h recovery. Blood glucose remained unchanged throughout 8.6 +/- 0.46 mM. role that gluconeogenesis might play removal post-exercise evaluated. Animals were run exhaustion 1.5 km/h on a thermostatted C. (n 43) ran 6.9 0.75 prior exhaustion. sacrificed and muscles both hindlimbs removed stimulated Hz for min, reducing twitch tension 6% prestimulus tension. Fatigued then split into red white fiber bundles incubated or Ringer solution plus 20 lactate. In August, demonstrated rate synthesis approximately 1 mg/(g . h). December, synthesized reduced not statistically different than without Glycogen evident either August December. period peak gluconeogenic coincides with field active season Dipsosaurus.(ABSTRACT TRUNCATED AT 250 WORDS)