Comparison of biochemical and physiological characteristics among white, pink, and red muscle fibers in carp (cultured)

As part of a program to clarify the influence of difference of muscle fiber types in ordinary muscle on rigor mortis progress of fish, this study comp ared and examined the biochemical and physiological characteristics of musc le fiber types in relation to the muscular contraction and relaxation among white (W), pink (P), and red (R) muscle fibers of carp (cultured). The con tents of ATP-related compounds and glycogen just after killing, lactate deh ydrogenase activity, and myofibrillar Mg2+-ATPase activity in ordinary musc le were higher in the order of W > P > R, R is approximately equal to P >> W, W is approximately equal to P >> R, and P greater than or equal to W >> R, respectively. From these results, it was suggested that the capacity of anaerobic energy supply for rigor mortis progress might be higher in the or der of pink muscle fiber, white muscle fiber, and red muscle fiber. The max imum level reached by caffeine contraction was considerably higher in pink muscle fiber than in white muscle fiber, in the order of P >> W > R. Howeve r, sarcoplasmic reticulum (SR) Ca2+-ATPase activity, SR Ca2+ uptake rate, a nd SR Ca2+ release rate were not higher in pink muscle fiber than in white muscle fiber, in the order of P W >> R, W > P > R, and W > P > R, respectiv ely. The surface area and volume percentages of SR against sarcomere were h igher in the order of P > W > R and P >> W > R, respectively, and well supp orted the result of caffeine contraction. The superprecipitation reaction o f actomyosin was higher in the order of P greater than or equal to R >> W. This result suggested that the characteristic of actomyosin in relation to muscular contraction may be markedly different among white, pink, and red m uscle fibers.