1. 1. Muscle samples from the M. gluteus médius were obtained from six Quarter Horses (QH), six Thoroughbreds (TB), and five Standardbreds (SB) to determine carnosine values and fiber type percentages. 2. 2. Muscle biopsies were for fiber type percentages and carnosine concentration. 3. 3. QH had a lower percentage of slow twitch oxidative fibers and a higher percentage of past twitch glycolytic fibers than SB or TB. 4. 4. Fast twitch oxidative-glycolytic fibers were lowest in the QH. 5. 5. The QH had mean carnosine values significantly greater (P < 0.01) than the mean values for SB and TB. 6. 6. Across breeds muscle carnosine concentration was positively correlated (P < 0.05; r = 0.53) with fast twitch glycolytic fiber percentage and negatively correlated (p < 0.05; r = - 0.51) with fast twitch oxidative fiber percentage. 7. 7. Free intramuscular carnosine is believed to function as an intracellular buffer. Since carnosine was highest in the muscle of horses with the greatest percentage of fast twitch glycolytic fibers, these data are consistent with the proposed function of this dipeptide.
|Number of pages||3|
|Journal||Comparative Biochemistry and Physiology -- Part A: Physiology|
|State||Published - 1990|
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