The role of nitric oxide in proteoglycan turnover by bovine articular cartilage organ cultures
Küçük Resim Yok
Tarih
1996
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Monolayer cultures of articular chondrocytes synthesize large amounts of nitric oxide (NO) following exposure to IL-1. The latter has antianabolic and procatabolic activities on these cells, but little is known about the role, if any, of NO in the integrated metabolic pathways of the chondrocyte. In the present study, the role of endogenously produced NO in both the synthesis and degradation of proteoglycans was investigated for the first time. Bovine articular cartilage slices exposed to 20 U/ml human rIL-1ß (hrIL-1ß) synthesized large amounts of NO for 1 to 2 days, after which production fell to a steady state level ~20% of the peak value for the remainder of the 14- day incubation. The NO synthase inhibitor, N-monomethyl L-arginine (L-NMA, 1 mM), blocked NO production and enhanced the acute catabolic effects of hrIL- 1ß in cartilage derived from both calves and adult animals. However, in late cultures, release of proteoglycans was reduced in the presence of L-NMA. The proteolytic activity in conditioned medium of these cultures (measured as caseinolytic activity) was enhanced by L-NMA; however, this inhibitor did not affect the rates of synthesis of proteoglycans. Although NO is widely assumed to be a mediator of cartilage catabolism, our data suggest that it may instead have an acute protective effect. Whether this effect is maintained chronically is less clear.
Açıklama
Anahtar Kelimeler
Kaynak
Journal of Immunology
WoS Q Değeri
Scopus Q Değeri
N/A
Cilt
156
Sayı
3
