The influence of doxycycline on articular cartilage in experimental osteoarthrosis induced by iodoacetate.

The experiment was performed on 36 Wistar rats. On the first day of the experiment iodoacetate was administered to the left posterior knee joint of the 18 rats which composed Group I. The second group of 18 rats received additionally doxycycline (doxy) through the gastric tube in doses comparable with those of doxycycline used in humans. The experiment lasted 21 days. The animals were sacrificed after 7, 14 and 21 days in groups of 6 rats each. In sections stained with Safranin 0 semiquantitative histochemical intensity tests were performed on articular cartilage glycosaminoglycans (GAG) using a four-point scale (0-3). In the first group examined destructive lesions in the articular cartilage and weak reactivity on GAG were noted at all stages of the experiment. The intensity of GAG staining was higher in the second group after 14 and especially after 21 days, which may suggest a protective action of doxy on articular cartilage.