Immunohistochemical quantification of fast-myosin in upper hind limb muscles of the pig

摘要

Using an immunohistochemical microquantification technique, in which frozen sections mounted on glass slides are used as analogues of the antigen precoated wells of the enzyme-linked immunosorbent assay-plates and the structure is well preserved, weexamined the contents of fast-myosin isoforms in different portions of 17 hind limb muscles of female Duroc pigs. High fast-myosin levels (more than 200 mg/g of total protein) were observed in the gluteus superficialis, gluteus medius, vastus lateralis,biceps femoris and tensor fasciae latae muscles, and low levels (less than 75 mg/g) in the gluteus profundus, vastus intermedius and semimembranosus muscles. Fast-myosin-positive fibers were distributed more in the superficial regions than in the deeperregions in the hind limb muscles. The highest population of type I fibers was seen in the vastus intermedius muscle (78 percent), and the lowest in the gluteus medius muscle (10 percent). The highest number of type IIA fibers was seen in the rectus femoris muscle (29 percent), while the lowest was seen in the semimembranosus muscle (14 percent). The highest number of type IIB fibers was found in the gluteus medium muscle (73 percent), and the lowest in the vastus intermedius muscle (7 percent). Good correlation between the microquantification and histochemical analysis was seen. The histological structure of the muscles was well preserved during microquantification, and this technique could be used in research projects to study the contractile properties of the muscles and evaluate the meat qualities of pig muscles.