Reduced calcium-dependent proteinase activity in cimaterol-induced muscle hypertrophy in lambs.
The purpose of this study was to reveal the possible relationships between total Ca2+-dependent proteinase (CDP) and micromolar-Ca2+-dependent proteinase (microM CDP) activity and cimaterol-induced hypertrophy of skeletal muscle. Dietary administration of 10 ppm cimaterol to finishing lambs reduced microM CDP activity in longissimus muscle (LD) by 55% (P less than .01) and 70% (P less than .02) after 3 and 6 wk of treatment, respectively. Total CDP activity was unaffected by cimaterol at both treatment intervals. The reduced microM CDP activity was not associated with a reduced yield of enzyme extract from the muscle. Cimaterol treatment increased the cross-sectional area of the LD by 23.5% at 3 wk and by 35.6% at 6 wk (P less than .001). Cimaterol also increased (P less than .001) the masses of semitendinosus, semimembranosus and biceps femoris by 26%, 32.4% and 24.5%, respectively. These results suggest that cimaterol-induced muscle hypertrophy may be attained in part by reduction of myofibrillar protein degradation.
Wang
S Y
SY
Dept. of Anim. Sci., Cornell University, Ithaca, NY 14853.
Beermann
D H
DH
D000818:Animals; D002154:Calpain / Q000378:metabolism*; D004983:Ethanolamines / Q000494:pharmacology*; D006984:Hypertrophy / Q000139:chemically induced / Q000201:enzymology / Q000662:veterinary; D008297:Male; D024510:Muscle Development; D009132:Muscles / Q000187:drug effects / Q000201:enzymology*; D012756:Sheep / Q000378:metabolism*
D004983:Ethanolamines; D002154:Calpain; C047411:cimaterol