Levy J, Ornoy A, Atkin I
Acta Anat (Basel). 1980;106(3):360-9. doi: 10.1159/000145201.
Tetracyclines are known to interfere with bone calcification. We therefore studied their effects on matrix vesicle production and initial calcification of cartilage. 15-day-old rats were injected intraperitoneally with oxytetracycline 100 mg/kg, 6 consecutive injections every 12 h. Epiphyseal plates were examined by scanning and transmission electron microscopy and compared to light microscopy findings. It was found that high doses of tetracyclines cause degeneration of the chondrocytes in the proliferating and hypertrophic zones. Chondrocytes had short processes with only few matrix vesicles covering their surface. In the chondrocytic lacunae of the longitudinal septa of hypertrophic and calcifying cartilage there were fewer matrix vesicles as compared to controls, and their ability to aggregate and form mineralized calcospherites was impaired. This was further proven when bones were immersed in 7% NaOCl or ashed, as minerals containing calcospherites were hardly seen. It is therefore presumed that interference with intracellular and probably extracellular accumulation of calcium by tetracycline might inhibit matrix vesicle production and aggregation, thus inhibiting calcification.
已知四环素会干扰骨骼钙化。因此，我们研究了它们对软骨基质小泡生成和初始钙化的影响。给15日龄大鼠腹腔注射100mg/kg土霉素，每12小时连续注射6次。通过扫描电子显微镜和透射电子显微镜检查骨骺板，并与光学显微镜检查结果进行比较。结果发现，高剂量四环素会导致增殖区和肥大区的软骨细胞变性。软骨细胞的突起短，表面仅有少量基质小泡。与对照组相比，肥大和钙化软骨纵向隔的软骨细胞陷窝中的基质小泡较少，其聚集和形成矿化钙球的能力受损。当将骨骼浸入7%次氯酸钠中或灰化时，这一点得到了进一步证实，因为几乎看不到含有钙球的矿物质。因此推测，四环素对细胞内以及可能对细胞外钙积累的干扰可能会抑制基质小泡的产生和聚集，从而抑制钙化。
