Histoenzymatic Characteristics and the Size of Skeletal Muscle Fibers in the Guinea Fowl Numida meleagris

Abstract

The myofiber type profiles of the following skeletal muscles of the Guinea Fowl were examined histochemically : M. obliquus externus abdominis, M. obliquus internus abdominis, M. trapezius, M. latissimus dorsi, M. pectralis superficialis, M. pectralis profundus, M. triceps brachii, M, extensor carpi radialis longus, M. sartorius, M. rectus femoris, M. adductor magnus, M semitendinosus, M. semimembranosus, M. gastrocnemius-caput latelare, M. gastrocnemius-caput mediale, and M. soleus. According to the histoenzymatic reaction pattern (succinate dehydrogenase, malate dehydrogenase, nicotinamide adenine dinucleotide tetrazolium reductase, lactate dehydrogenase, beta hydroxybutylate dehydrogenase, alpha glycerophosphate dehydrogenase, aldolase, phosphrylase, and myosin adenosine triphosphatase), myofibers were divided into three types, i.e. fast-twitch-glycolytic (FG), fast-twitch-oxidative-glycolytic (FOG) and slow-twitch-oxidative (SO) types. Furthermore, according to the intensity of the enzyme reactions, FG type fibers were subdivided into two types, FOG type fibers into four types, and SO type fibers into three types.FG1, FOG2, FOG3, SO1 and 503 type fibers could be observed in M. obliquus externus abdominis. FG2, FOG2, FOGS, SOl and S02 were observed in M. obliquus internus abdominis. SOl and SO2 were observed in trapezius. FG1, FOG2, FOG3, SO1 and SO2 were observed in M. lattissimus dorsi. FG1, FOG3, FOG4 and SO2 were observed in M. pectralis superficialis, M. pectralis profundud and M. semitendinosus. FG1, FOG3 and S02 were observed in M. triceps brachii and M, extensor carpi radialis longus. FGI, .FOGI, FOG3, SOl and S02 were observed in M, sartorius and M. rectus femoris. FG2, FOG2, FOG3 and SOl were observed in M. adductor magnus. FG2, FOG2, FOG3, S02 and SO3 were observed in M. semimembranosus. FGI, FOG1, FOG2 and SO1 were observed in M. gastrocnemius-caput raterale and mediale. FG2, FOG2, FOGS, 501 and S02 were observed in M. soleus.The ratio of the number of the FG type fibers was higher than the fibers of other types with exception of M. obliquus externus abdominis, M. obliquus internus abdominis, M. rectus femoris, M, adductor magnus, M, semimembranosus and M. soleus. In these exceptional muscles, FOG type fibers were dominant.M. trapezius was composed of SO type fibers. The diameter of myofiber showed the largest value in FG type fibers with the exception of M. trapezius and M. soleus, and showed the smallest value in SO type fibers with the exception of M. trapezius, M. adductor magnus, M. semimembranosus, M. gastrocnemius-caput latelare, M. gastrocnemiuscaput mediale and M. soleus. The variation of myofiber was largest in FG type fibers.The pH stability of myosin ATPase activity varies with the muscle fiber types. The range of pH stability at alkaline pH range was more extensive in FG type fibers than in the other types of myofiber, whereas at acidic pH range SO type fibers were more extensive in the range of pH stability than other myofiber types.