Evaluation of inhibitory effects of doxorubicin on collagenase using a bovine placentome model

The chemotherapeutic antibiotic doxorubicin (Adriamycin) was reported to inhibit bacterial collagenase activity when tested on both a synthetic substrate and intact collagen. Our objective was to establish whether doxorubicin would inhibit bacterial collagenase activity on a bovine placentome model. Metabolically active, isolated bovine placentomes were infused, via umbilical vessels, with a mixture of bacterial collagenase and doxorubicin. Six experimental groups were used. Group (1) comprised of saline controls; (2), collagenase at 1,200 U/cc; (3, 4, and 5), collagenase (1,200 U/cc) plus doxorubicin at 0.04 mg/cc, 0.02 mg/cc, 0.01 mg/cc, respectively; (6), doxorubicin at 0.02 mg/cc. After 5 hrs of incubation (39 degrees C), manometric pressure (needed to separate caruncle and cotyledon), caruncle-cotyledon interface hydroxyproline (collagenolysis), and total protein (proteolysis) were determined. Results indicated no (P > 0.01) inhibition of collagenase by doxorubicin. We concluded that doxorubicin (at above dosages) is not an inhibitor for bacterial collagenase when tested on bovine placentomes.