In vitro evidence for effects of magnesium supplementation on quinolone-treated horse and dog chondrocytes.
Quinolones and magnesium deficiency cause similar lesions in joint cartilage of young animals. Chondrocytes cultivated in the presence of quinolones and in Mg-free medium show severe alterations in cytoskeleton and decreased ability to adhere to the culture dish. We investigated whether Mg2+ supplementation can prevent quinolone-mediated effects on chondrocytes in vitro. Chondrocytes cultivated in Dulbecco's modified Eagle's medium/HAM's F-12 medium were treated with ciprofloxacin (80 and 160 microg/ml) and enrofloxacin (100 and 150 microg/ml). Mg2+ was added at a concentration of 0.0612 mg/ml (MgCl) and 0.0488 mg/ml (MgSO4) or a triple dose. In addition, cells were cultivated in Mg-free medium and accordingly treated with Mg2+ supplementation. After 5 days in culture, the number of adherent cells per milliliter was determined. The number of chondrocytes in quinolone-treated groups decreased to 12-36% that of the control group within the culture period. With Mg2+ supplementation, the number of attached cells increased to 40-70% that of control cells. The threefold dose of Mg2+ led to better results than did the single dose. Cell proliferation tested by immunohistochemical staining with Ki67 (clone MIB5) decreased from 70% in control groups to 55%, 48%, and 30% in enrofloxacin-treated groups in a concentration dependent manner (50, 100, and 150 microg/ml). Addition of Mg2+ did not increase the rate of cell proliferation. These results suggest that a great part of quinolone-induced damage is due to magnesium complex formation, as Mg2+ supplementation is able to reduce the effects in vitro. However, quinolone effects on cell proliferation seem to be an independent process that is not influenced by magnesium supplementation.
Egerbacher
M
M
Institute of Histology and Embryology, University of Veterinary Medicine, Vienna, Austria.
Wolfesberger
B
B
Gabler
C
C
D000818:Animals; D000890:Anti-Infective Agents / Q000009:adverse effects / Q000494:pharmacology*; D002358:Cartilage, Articular / Q000166:cytology; D002448:Cell Adhesion / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D048429:Cell Size / Q000187:drug effects; D002478:Cells, Cultured; D019902:Chondrocytes / Q000187:drug effects* / Q000473:pathology; D002939:Ciprofloxacin / Q000009:adverse effects / Q000494:pharmacology*; D019587:Dietary Supplements; D004285:Dogs; D000077422:Enrofloxacin; D005260:Female; D024841:Fluoroquinolones; D006736:Horses; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000737:chemistry; D008274:Magnesium / Q000494:pharmacology*; D015363:Quinolones / Q000009:adverse effects / Q000494:pharmacology*
D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D019394:Ki-67 Antigen; D015363:Quinolones; D000077422:Enrofloxacin; D002939:Ciprofloxacin; D008274:Magnesium