Existence of parvalbumin and biochemical characterization in quail and pigeon skeletal muscles with different fiber type compositions.

The localization of parvalbumin was determined in skeletal muscles with different fiber type compositions from quails (Coturnix japonica) and pigeons (Columba livia) by sandwich ELISA. The biochemical profiles of these muscles were evaluated by the assay of total lactate dehydrogenase (LDH) activity as well as the LDH isozymes for anaerobic metabolism, and by the analysis of myoglobin for aerobic metabolism. The quail fast posterior latissimus dorsi (PLD) with a lower myoglobin content and higher LDH activity or M-type isozyme pattern was assessed as containing primarily fast-twitch glycolytic and oxidative-glycolytic (FG/FOG) fibers, and the mixed sartorius (SA) in quails and pigeons was shown to be composed mostly of FOG fibers because of the intermediate myoglobin content and LDH activity or H/M-type isozyme pattern. Parvalbumin, which functions as a relaxing factor in the fast-twitch fibers, was present in PLD and SA in significant amounts, whereas it was undetectable in quail anterior latissimus dorsi (ALD) and pigeon latissimus dorsi (LD) which contain exclusively slow-tonic (ST) fibers with the lowest LDH activity or predominant H-type isozyme characteristics. The pectoralis superficialis (PS) and pectoralis profundus (PP) muscles from quails and pigeons seem to consist mostly of FG/FOG fibers because of the highest myoglobin contents and LDH activities or M-type and H/M-type isozyme patterns. Despite fast-twitch fiber compositions, parvalbumin was absent from these pectoralis muscles. The tetanic contraction induced in avian fast-twitch pectoralis fibers during flapping flight might be independent of a function of parvalbumin as a relaxing factor.

Distribution of parvalbumin in specific fibre types of chicken skeletal muscles.

1. The distribution of parvalbumin (PA), which functions as a relaxing factor in the skeletal muscles, was examined in slow anterior latissimus dorsi (ALD), fast posterior latissimus dorsi (PLD), mixed sartorius (SA), pectoralis superficialis (PS) and pectoralis profundus (PP) muscles from chickens. 2. The biochemical characteristics of these muscles were confirmed by the assay of total lactate dehydrogenase (LDH) activity as well as the LDH isozymes for anaerobic metabolism, and by the photometrical analysis of myoglobin for anaerobic metabolism, and by the photometrical analysis of myoglobin for aerobic metabolism. 3. PA in individual muscles was determined by a sandwich ELISA and was demonstrated by 2-dimensional polyacrylamide-gel electrophoresis. 4. Because of poor myoglobin and higher LDH activity or M-type isozyme pattern, the PLD was confirmed as containing primarily fast-twitch glycolytic and oxidative-glycolytic (FG/FOG) fibres, while the SA was shown to be composed mostly of FOG fibres because of the highest myoglobin content and the intermediate LDH activity or H and M-type isozyme pattern. PA content was high and variable in both PLD and SA. 5. PA was undetectable in the ALD which appears to contain exclusively slow-tonic (ST) fibres, being verified by its myoglobin-rich nature and lowest LDH activity or predominant H-type isozyme characteristics. PA was absent from the PS ad PP, which probably contain predominantly FG fibres because of negligible amounts of myoglobin and the highest LDH activities or M-type isozyme pattern.