Avaliação qualitativa e quantitativa de glicosaminoglicanos em pacientes com osteoartrite

Abstract

Articular cartilage is na avascular tissue composed of chondrocytes scattered in an abundant extracellular matrix (ECM) that lines the joint surfaces and protects the bone ends. In addition to the intersticial fluid, the ECM is composed of proteoglycans, glycosaminoglycans (GAGs) and glycoproteins. Joint diseases such as osteoarthritis (OA), promote the degradation of articular cartilage and subchondral bone sclerosis, leading to chronic pain and functional impairment of the joints. In this context, the quantification of GAGs is used as a means to study the physiological or pathological changes of articular cartilage. The objective this study was to evaluate the biochemical changes of the articular cartilage of human and rat normal or affected by OA. The human cartilage were obtained from patients submitted to arthroplasty for OA or fracture. Male Wistar rats (150-180g) were submitted to the anterior cruciate ligament transection (ACLT). Sham group was submitted to only to surgery without transection. Initialy, the cartilage samples were submitted to the action of the enzymatic complex PROLAV 750R, getting to the end of the process, the GAGs. These were identified and quantified in agarose gel (0.6%) and molar mass was assessed in polyacrylamide gel (6% w/v). The results were expressed as mean ± standard error of mean (S.E.M.) were submitted to ANOVA and Tukey’s test (P<0.05) or “t” test of Student (P<0.05).In rats, the effective proteolysis was significantly decreased after 70 days of ACLT (P<0.05). In the quantification of GAGs, there was a significant increase in GAG content after 70 days of ACLT. In humans, the percentage of mass degraded by PROLAV was altered by presence of OA. The OA patients under 80 years of age showed a significant increase in the amount of GAGs compared to the control group. In the electrophoretic mobility, GAGs of patients with OA showed abnormalities of the molar mass. These findings show that both cartilage from patients affected by OA as experimental animals subjected to OA have lower effective proteolysis, increasing the amount of CS and alteration of the molar mass.