ENZYME-ACTIVITIES OF GLYCOGEN-METABOLISM AND MITOCHONDRIAL CHARACTERISTICS IN MUSCLES OF RN(-) CARRIER PIGS (SUS-SCROFA-DOMESTICUS)

High glycogen content and abnormal mitochondria have been seen in musc les from RN(-) carrier pigs in a previous work. Glycogen synthase, bra nching enzyme, phosphorylase and debranching enzyme activities, and mi tochondrial characteristics were studied in normal and RN(-) carrier p igs. Branching enzyme activity was higher (P < 0.01) and glycogen synt hase activity tended to be higher in longissimus dorsi muscle from RN( -) carrier pigs compared to normal pigs. There were no differences in the activities of either phosphorylase and debranching enzyme between both types of pigs. Citrate synthase activity and mitochondrial respir ation were slightly higher in muscle from RN(-) pigs compared to norma l pigs. Glycogen content in muscle from RN(-) pigs could result from t he imbalance between anabolic and catabolic enzyme activities of glyco gen metabolism. The higher specific activity in mitochondria of RN(-) pigs muscle might be the compensatory effect of an abnormal glycolytic metabolism.