A new test method for the standardized evaluation of changes in the ultrastructure of chondrocytes.

By means of a new ultrastructural test system, which is based on standardized morphometry and statistical evaluation, we are able for the first time to quantify changes in the cell metabolism of chondrocytes in the articular cartilage. To compare anti-inflammatory substances of different structure, different absorption characteristics and pharmacokinetics as regards their effect on rat cartilage, we used an equieffective dosage of the different anti-inflammatory drugs. Dexamethasone as steroidal and indomethacin and phenylbutazone as classical non-steroidal anti-inflammatory drugs (NSAIDs) were administered in an ED50 dosage referred to provoked arthritis over 12 weeks, using the same mode of administration. The standardized results of untreated rats weighing 300 and 450 g were used as the controls. Dexamethasone brings about massive degenerative changes in the ultrastructure of the vital chondrocyte. Under indomethacin and phenylbutazone the metabolic activity of the chondrocyte is inhibited to a much lesser extent. The damage to the chondrocyte after treatment with dexamethasone, indomethacin and phenylbutazone cannot be regarded as minimal but in some cases is tolerable as regards the benefit/risk ratio in the treatment of rheumatoid diseases.