1. In vivo effect of a beta-adrenergic agonist on activity of calcium-dependent proteinases, their specific inhibitor, and cathepsins B and H in skeletal muscle.
- Author
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Kretchmar DH, Hathaway MR, Epley RJ, and Dayton WR
- Subjects
- Animals, Calcium-Binding Proteins isolation & purification, Calpain antagonists & inhibitors, Calpain isolation & purification, Cathepsin B isolation & purification, Cathepsin H, Cathepsins isolation & purification, Chromatography, Ion Exchange, Female, Isoenzymes isolation & purification, Kinetics, Reference Values, Sheep, Adrenergic beta-Agonists pharmacology, Calcium-Binding Proteins metabolism, Calpain metabolism, Cathepsin B metabolism, Cathepsins metabolism, Cysteine Endopeptidases, Isoenzymes metabolism, Muscles enzymology, Pyridines pharmacology
- Abstract
DEAE-Sephacel and phenyl-Sepharose chromatography were compared as methods for separating and quantitatively isolating calpain I, calpain II, and calpastatin from lamb muscle extracts. DEAE-Sephacel chromatography gave greater than 90% recovery of all three proteins, while phenyl-Sepharose gave only 70, 66, and 48% of the DEAE recovery of calpain I, calpain II, and calpastatin, respectively. Additionally, DEAE-Sephacel chromatography was shown to effectively separate calpastatin and calpain I. Consequently DEAE-Sephacel appears to be superior to phenyl-Sepharose for quantitative isolation of the components of the calcium-dependent proteinase system from muscle extracts. Dietary administration of beta-agonist (L-644, 969; Merck Sharpe & Dohme Research Laboratories) decreases extractable calpain I activity in lamb longissimus dorsi (LD) muscle by 10-14% (P less than 0.05), increases calpain II activity by 34-42% (P less than 0.001), and increases calpastatin activity by 59-75% (P less than 0.001). Additionally, net cathepsin B activity is reduced by 30% (P less than 0.05) in the LD of beta-agonist-treated lambs. Reduced activity of the calcium-dependent or catheptic proteinase systems may contribute to the increased protein accretion in muscles of beta-agonist-treated lambs.
- Published
- 1989
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