Exercise protects against articular cartilage degeneration in the hamster

Abstract

Objective. It has been reported that osteoarthritis can occur in hamsters. The present study was undertaken to determine the effects of exercise on the composition of articular cartilage and synovial fluid and on the development of cartilage degeneration in these animals.Methods. Young (2.5-month-old) group-housed hamsters were compared with 5.5-month-old hamsters that had undergone 3 months of daily wheel running exercise (6-12 km/day) or 3 months of sedentary, individually housed living. The condition of the femoral condyles was determined by scanning electron microscopy in 12 exercising hamsters, 12 sedentary hamsters, and 6 of the young controls. The content of proteoglycan, hyaluronic acid, hydroxyproline, and proline in synovial fluid and patellar cartilage was measured.Results. By scanning electron microscopy, the femoral articular cartilage was smooth and undulating in young controls and older exercising hamsters. In contrast, the femoral condyles were fibrillated in all 12 of the sedentary hamsters. There was no difference in the patellar cartilage collagen content between the 3 groups, but proteoglycan content and synthesis were lower in the patellar cartilage of the sedentary group. Synovial fluid volume was also decreased in the sedentary group compared with the young controls or the older exercising hamsters.Conclusion. A sedentary lifestyle in the hamster leads to a lower proteoglycan content in the cartilage and a lower synovial fluid volume. These changes are associated with cartilage fibrillation, pitting, and fissur-

Ascorbic acid increases the severity of spontaneous knee osteoarthritis in a guinea pig model

“…Hydroxyproline analysis. The hydroxyproline content of cartilage extracts was determined according to the HPLC method of Otterness et al (25), with minor modifications. Briefly, after acid hydrolysates were derivatized with 9-fluorenylmethoxycarbonyl, they were loaded directly into a 100-l injection loop in 50% solvent B (acetonitrile/methanol/ water; 40%/40%/20% [v/v/v]) at a flow rate of 1.5 ml/minute.…”

Effect of recreational physical activities on the development of knee osteoarthritis in older adults of different weights: The Framingham Study

“…Because dynamic loading of cartilage has a trophic effect on cartilage (1), frequent dynamic loading, especially in a healthy range, would cause cartilage to become thicker (2), and if cartilage thickness prevents disease, OA might occur less frequently in individuals engaging in regular activity. In most animal studies, weight-bearing exercise has been shown to protect against the development of OA (3,4), but in one strain of centrally stimulated animals that run almost constantly, there is a high rate of cartilage loss versus control animals (2,3).…”

Resistance exercise recovers the structure of cartilage and synovial membrane of the ankle joint of rats after sciatic compression

“…Articular rigidity and a decreased range of motion, due to lower weight bearing caused by nerve injury, may be responsible for thickening of the synovial membrane 23 , leading to a lower level of proteoglycans 45 , which interferes with the production of synovial fluid and consequently reduces the supply of nutrients to the cartilage 23,35 . According to Kojima, Hoso, Watanabe, Matsuzaki, Hibino, Sasaki 46 , these changes may be related to the presence of flocculation, corrosion and cracks in the articular cartilage.…”