ABSTRACT
PCR-RFLP, periodic acid Schiff (PAS) and myosin heavy chain (MHC) immunohistochemistry were employed to survey the relationships between the genotypes of the myogenin gene (myog) and the histological characteristics of the muscle and other postmortem traits in the Jinghua×Pietrain (JP) F(2) crossbred pigs. The muscle fibers were classified into three groups according to their PAS-reactivity: PAS(-), PAS(+â¼++), and PAS(+++) and accounted for approximately 16%, 74% and 10% of the total muscle, respectively. MHC immunohistochemistry was used to categorize muscle fibers into either slow or fast fibers; the proportions of slow and fast fibers were 6% and 94%, respectively. Two different cleavage patterns and three genotypes (AA, AB and BB) were identified and their frequencies were 0.4087, 0.4986 and 0.0928, respectively, for the three genotypes and 0.6580 and 0.3420, respectively, for cleavage patterns A and B. Different genotypes were variably associated with cross-sectional area (p=0.074), water-holding capacity (p=0.002), pH (p<0.001) and carcass temperature (p<0.001) of the loin muscle. Different genotypes showed marked correlation with the L value (p<0.001), a value (p=0.002), and b (p<0.001) of the Minolta meat color index. The genotypes were also significantly related to the cross-sectional area (p<0.001), diameter (p<0.001), aspect ratio (p<0.001) and the density (p<0.001) of muscle fibers from the longissimus dorsi muscle. The results also revealed that the genotypes showed no significant association with the circularity (p=0.132) or the percentage of intramuscular connective tissue (p=0.193).
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of six cold traditional Chinese medicine on the energy metabolism factors in rats skeletal muscle.</p><p><b>METHOD</b>The activity of Na(+)-K(+) -ATPase, Ca(2+) -ATPase and succinate dehydrogenase (SDH), the content of muscle glycogen, and the mRNA expression of skeletal muscle uncoupling protein 3 (UCP3) were measured after rats having been administrated with water extracts of Radix Sophorae Flavescentis, Fructus Gardeniae, Cortex Phellodendri, Radix Scutellariae, Rhizoma Coptidis, and Radix Gentianae respectively at the dose of 6.0, 7.0, 8.4, 6.0, 7.0, 4.0 g x kg(-1) for 30 days.</p><p><b>RESULT</b>The activity of Na(+) -K(+) -ATPase has been depressed significantly and the content of skeletal muscle glycogen has been increased remarkably by six cold traditional Chinese medicine. The decreased tendency has been found on activity of Ca(2+) -ATPase and SDH, only the Radix scutellariaeg group decreased the Ca(2+) -ATPase activity significantly (P < 0.05), the SDH activity was decreased high significantly by Radix scutellariae, Cortex Phellodendri, Radix Gentianae and significantly by Rhizoma Coptidis. The mRNA expression of UCP3 has been decreased high significantly by all five cold traditional Chinese medicine except Cortex Phellodendri group with the decreased tendency of UCP3 mRNA expression.</p><p><b>CONCLUSION</b>The cold traditional Chinese medicine has the significant effects on the skeletal muscle energy metabolism by decreasing the utlization of the glucose and the activity of mitochondria SDH to reduce the production of ATP, and depressing the activity of Na(+)-K(+) -ATPase and Ca(2+) -ATPase to cut down the consumption of ATP, by decreasing the mRNA expression of UCP3 to decrease the heat production.</p>
