Connective tissue metabolism in muscular dystrophy. Amino acid composition of native types I, III, IV and V collagen isolated from the gastrocnemius muscle of embryonic chickens with genetic muscular dystrophy

Fiber Metabolism, Procollagen and Collagen Type III Immunoreactivity in Broiler Pectoralis Major Affected by Muscle Abnormalities

“…Overall, the heterogeneous staining to procollagen and collagen type III observed in the fast-growing hybrid (aside from the type of abnormality) might be also explained by the eventual changes in amino acid composition previously observed in collagen isolated from dystrophic chickens [11]. Indeed, a selective removal of the polar side-chains and their replacement with non-polar amino acids was observed and resulted in a weakened helical structure of the collagen fibrils, altering both the functional and structural traits of the molecules [11]. With regard to WS, the immunoreactivity for procollagen and collagen type III observed in these muscles suggests an intense collagen synthesis taking place.…”

“…In this regard, collagen type III is mainly found in association to type I and plays a key role in its fibrillogenesis [9]. Indeed, because of its inherent structure, collagen type III may contribute to the extensibility and elasticity of the connective tissue [36], and its altered deposition has been previously associated with various muscular dystrophies and fibrosis [11,12]. Overall, the heterogeneous staining to procollagen and collagen type III observed in the fast-growing hybrid (aside from the type of abnormality) might be also explained by the eventual changes in amino acid composition previously observed in collagen isolated from dystrophic chickens [11].…”

“…Indeed, because of its inherent structure, collagen type III may contribute to the extensibility and elasticity of the connective tissue [36], and its altered deposition has been previously associated with various muscular dystrophies and fibrosis [11,12]. Overall, the heterogeneous staining to procollagen and collagen type III observed in the fast-growing hybrid (aside from the type of abnormality) might be also explained by the eventual changes in amino acid composition previously observed in collagen isolated from dystrophic chickens [11]. Indeed, a selective removal of the polar side-chains and their replacement with non-polar amino acids was observed and resulted in a weakened helical structure of the collagen fibrils, altering both the functional and structural traits of the molecules [11].…”

“…Conflicting results have been found concerning the relationship between collagen content and meat texture. However, an increased deposition of collagen type III within the endomysial and perimysial compartments was found to be positively correlated with muscle toughness [10], and an altered deposition of this collagen type has been associated with the occurrence of muscular dystrophies and fibrosis [11,12]. Thus, being an "embryonic" connective tissue that is typically observed in developing/regenerating muscles, collagen type III and its precursor (procollagen type III) might play a role in the cellular processes, resulting in the development of WS, WB, and SM abnormalities.…”

Determination of the myofibrillar and connective tissue proteins in the bovine diaphragm

“…The accuracy of such calculations, however, will depend on the purity of elastin and the various collagen isotypes on which their Des or iDes, Lys(5-OH), and Pro(4-OH) contents are based. Although the structure and amino acid composition of purified collagens and elastin from various species (Table V) have been investigated quite thoroughly at the protein and gene levels (Miller and Gay, 1982;Foster, 1982;Paz et al, 1982;Cheah, 1985), there is a paucity of compositional data on skeletal muscle collagens and elastin, and the only biochemical studies that have been done on collagens and elastin of bovine skeletal muscle are those of Bendall (1967), Light and Champion (1984), and DeMichele et al (1985). Light et al (1985) have shown that the levels of six bovine skeletal muscle connective tissue in the epimysium, perimysium, and endomysium represent 1.2,4.7, and 0.3% of the total muscle dry weight, respectively.…”