Dietary 2-oxoglutarate mitigates gastrectomy-evoked structural changes in cartilage of female rats

Gastrectomy (Gx) leads to osteopenia/osteoporosis in humans and animals. However, little is known about the influence of Gx on the cartilage in this regard. Recent studies have demonstrated a protective effect of 2-oxoglutaric acid (2-Ox) on bone and cartilage. Hence, the purpose of this study was to investigate whether 2-Ox can mitigate eventual Gx-induced cartilage impairment. Twenty female Sprague-Dawley rats were subjected to Gx and randomly divided into two groups: Gx+2-Ox and Gx. Another 20 rats were sham-operated (ShO) and randomly divided into two groups: ShO+2-Ox and ShO. The daily dose of 2-Ox administered to the rats in the drinking water was 0.43 g per 100 g rat. After eight weeks, rats were euthanized and femora and tibiae were collected. Histology and histomorphometry analyses of the articular cartilage and the growth plate were done. Gx resulted in a 32% (+/- 44.5 femur, +/- 35.8 tibia) decrease in overall thickness of articular cartilage in both bones (femur: ShO 279.1 +/- 48.5 vs. Gx 190.2 +/- 38.4 mu m, tibia: ShO 222.9 +/- 50.3 mu m vs. Gx 151.3 +/- 52.6 mu m) (in some zones up to 58 +/- 28.0%), and in the growth plate up to 20% (+/- 22.4) (femur: ShO 243.0 +/- 34.0 vs. Gx 207.0 +/- 33.7 mu m, tibia: ShO 220.0 +/- 24.6 mu m vs. Gx 171.1 +/- 16.1 mu m). Gx altered the spatial distribution of thick and thin collagen fibers, and chondrocyte shape and size. 2-Ox administration prevented the reduction in both cartilages thickness (Gx+2-Ox: articular cartilage 265.2 +/- 53.8 mu m, 235.6 +/- 42.7 mu m, growth plate 236.7 +/- 39.2 mu m, 191.3 +/- 16.5 mu m in femur and tibia, respectively), and abolished the spatial changes in collagen distribution and structure induced by Gx. Gx affects cartilage structure and thickness, however, 2-Ox administration mitigates these effects and showed protective and stimulatory properties. Our observations suggest that dietary 2-Ox can be used to offset some of the changes in hyaline cartilage, in particular articular cartilage, following bariatric surgeries.