Effects of localized Pasteurella haemolytica infection on erythromycin-binding properties of bovine alpha-1-acid glycoprotein, albumin, serum, and tissue chamber fluids
Date
1994-10Author
Walker, James L.
Clarke, Cyril R.
Hague, Christinia M.
Bourne, David W. A.
Lessley, Bruce A.
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The in vitro erythromycin-binding properties of bovine alpha-1-acid glycoprotein (AAG) and albumin were studied by using equilibrium dialysis. In addition, the proportions of free erythromycin in bovine serum and tissue chamber fluid before and 4 days after inoculation of subcutaneous tissue chambers with Pasteurella haemolytica were measured. At a concentration of 5 micrograms/ml, erythromycin was moderately bound to AAG (39% +/- 4% free) and was only slightly bound to albumin (86% +/- 2% free). Scatchard analysis of the data describing binding to pure bovine AAG indicated that erythromycin was bound to a single high-affinity (6.45 x 10(4) M-1) site on the protein. At lower total concentrations of erythromycin, the free concentrations of the antibiotic were lower in serum samples collected after infection (49% +/- 3% at 5 micrograms of erythromycin per ml) than in those collected before inoculation (55% +/- 3% at 5 micrograms of erythromycin per ml). Inoculation had no effect on binding to macromolecules in chamber fluids. Inoculated tissue chambers served as a convenient model for studying the effect of infection on drug-macromolecule interactions in interstitial fluid.
Citation
Walker, J. L., Clarke, C. R., Hague, C. M., Bourne, D. W. A., & Lessley, B. A. (1994). Effects of localized Pasteurella haemolytica infection on erythromycin-binding properties of bovine alpha-1-acid glycoprotein, albumin, serum, and tissue chamber fluids. Antimicrobial Agents and Chemotherapy, 38(10), 2392-2397. https://doi.org/10.1128/AAC.38.10.2392