Distribution of fiber types in locomotory muscles of dogs

Abstract

The distribution of Type I and Type II fibers, as determined from histochemical estimation of myofibrillar ATPase activity, was studied within and among the locomotory muscles of the forelimb, trunk, and hindlimb of three mongrel dogs. All Type II fibers had high oxidative capacities as estimated from the histochemical assay for reduced nicotinamide adenine dinucleotide tetrazolium reductase, so they were not further divided into subpopulations. Furthermore, Type I and Type II fibers had similar oxidative potentials as indicated by both histochemistry and biochemistry. Type I fiber populations ranged between 14% and 100% in the muscles sampled. The highest percentages of Type I fibers were found in deep muscles of physiological extensor groups in the arm and thigh that serve to resist gravity (antigravity muscles) when the dog is in the quadrupedal standing position. More superficial muscles in these same groups had fewer Type I fibers. The patterns of Type I fiber distribution among muscles in the antigravity groups of the forearm and leg were the opposite of those in the arm and thigh, with the more superficial muscles of the distal limb segments having more Type I fibers than the deeper muscles. In all limb segments, muscle groups that do not serve to resist gravity did not show as much intermuscular variation. Type I fiber populations in these muscles did not exceed 50%. A stratification of fiber types also existed within muscles, both in extensor and flexor groups, with the deeper portions of the muscles having more Type I fibers than the more superficial portions.

Spatial distribution of fiber types within skeletal muscle fascicles from Standardbred horses

“…The results showed a predominance of type IIB fibers in the periphery of the fascicles, and of types I and IIA in the more central parts, which also agrees with studies of other mammals (James, 1971a(James, , b, 1972Ariano et al, 1973;Armstrong, 1980;Lexell et al, 1983;Armstrong and Phelps, 1984;Sjøstrøm et al, 1986Sjøstrøm et al, , 1992Hansen et al, 1987;Newsholme et al, 1988;Grotmol et al, 1988;Pernus and Erzen, 1991;Strøm and Holm, 1994). In the present study, type IIB fibers were identified by traditional myosin ATPase histochemistry.…”

“…Within each muscle in mammals, a shift in the proportions of fiber types depending on region has been observed, with more type I and type IIA fibers being found in the deeper regions than in the superficial parts (Armstrong, 1980;Totland and Kryvi, 1992;Karlström et al, 1994). In the present study this was also seen in the GM, but not in the ST muscle.…”

“…However, some studies of muscle fascicles describe a spatial fiber type distribution in which type IIB fibers occur most frequently along the fascicle periphery, while type I and IIA fibers are mostly located in the central parts (James, 1971a;Armstrong, 1980;Lexell et al, 1983Lexell et al, , 1984Sjøstrøm et al, 1986Sjøstrøm et al, , 1992Hansen et al, 1987;Newsholme et al, 1988;Grotmol et al, 1988;Pernus and Erzen, 1991;Manta et al, 1995;Cobos et al, 2001). In horse muscle, a predominance of type IIB fibers in the periphery of fascicles has also been observed (Snow and Guy, 1981).…”

Distribution Pattern of Muscle Fiber Types in the Perivertebral Musculature of Two Different Sized Species of Mice

“…For example, hindlimb muscles of the Etruscan shrew (2.2 g) and the greater white-toothed shrew (8.6 g) were compared with those of the mouse (35 g), the laboratory rat (200 g), and the guinea pig (350 g) (Peters et al, 1999;Jü rgens, 2002). In m. extensor digitorum longus, a muscle generally considered as fasttwitch, glycolytic (e.g., Close, 1972;Armstrong, 1980), only 5% Type I fibers in the rat and 6% in the guinea pig were observed, but no Type I fibers in the mouse (Peters et al, 1999;Jü rgens, 2002). In m. soleus, generally a slow-twitch, oxidative muscle dominated by Type I fibers (e.g., Close, 1972;Peter et al, 1972;Armstrong, 1980, Pearson and Young;, 100% of the muscle fibers were of Type I in the rat and the guinea pig, but only 50% in the mouse (Peters et al, 1999;Jü rgens, 2002).…”

Morphometry and Histochemistry of the Rectus abdominis Muscle Fibers of Tufted Capuchin Monkeys (Cebus apella Linnaeus, 1758)

“…When a muscled is involved in fast movement, there is a predominance of fiber types FG and FOG; whereas an antigravitational muscle, involved in the maintenance of a static posture, will show a predominance of SO fibers. Therefore, the composition of a skeletal muscle's fiber types may vary among species, according to their posture, and within the same animal among its muscles, depending on the type of activity performed Ariano et al (1973); Armstrong et al (1982).…”