METHODS OF ARTICULAR CARTILAGE SAMPLE PREPARATION FOR EVALUATION OF ITS HISTOLOGICAL STRUCTURE, TINCTORIAL PROPERTIES AND ELEMENT COMPOSITION

Objective - to develop optimal methods for preparation of articular hyaline cartilage samples for the comparative analysis of its histological structure and element composition in intact animals and in induced osteoarthritis. Material and methods. Articular cartilage of femoral condyles harvested from 5 intact (controls) and 5 experimental dogs with modeled osteoarthritis was studied. Semi-thin epoxy sections that were stained with methylene blue and methylene blue - basic fuchsin were studied with the photomicroscope Opton-3 (Opton, Germany). The surfaces of epoxy-embedded tissue blocks after preparation of semi-thin sections were studied by the method of X-ray electron probe microanalysis. Results. In intact animals, metachromatic reaction was more intensive in the direction from the articular surface to the subchondral bone. Electron probe microanalysis confirmed an uneven distribution of sulfur in the cartilage zones. In the series with induced osteoarthritis, fibrillation of the cartilage surface and loss of sulfur was marked in all cartilage zones. Decrease in the sulfur content in the intermediate and deep zones was accompanied by an increase in calcium content and appearance of phosphorus. In the calcified cartilage, an equal decrease in the content of calcium and phosphorus was observed as compared with intact levels. Conclusions. The results obtained demonstrate the possibilities of electron probe microanalysis in the investigation of the molecular mechanisms of chondral pathology development.

articular cartilage, metachromasia, osteoarthritis, X-ray electron probe microanalysis