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.
Institute of Histology and Embryology, University of Veterinary Medicine, Vienna, Austria.
M
M
Egerbacher
B
B
Wolfesberger
C
C
Gabler
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