一氧化氮合酶抑制剂对软骨修复组织蛋白多糖代谢和胶原表达的影响

目的研究诱导型一氧化氮合酶（iNOS）抑制剂对软骨修复组织蛋白多糖代谢和胶原表达的影响。方法双侧股骨髁间关节面全层软骨缺损新西兰大白兔24只，随机均分为对照组、骨形态发生蛋白（BMP）组和iNOS抑制剂S-甲基异硫脲（SMT）组。术后1年处死动物。应用组织切片番红O-快绿染色检测蛋白多糖，苦味酸-天狼猩红染色检测胶原的分布情况，利用图像分析技术检测糖胺聚糖含量和胶原的表达以及软骨厚度。结果术后1年，SMT组软骨修复组织番红O-快绿染色百分率（89．28％）明显高于BMP组（36．54％）和对照组（13．4％），SMT组软骨修复组织番红O-快绿染色平均灰度值（134．5）分别为BMP组（56．8）和对照组（26．4）的2．5倍和7倍。修复组织软骨平均厚度，SMT组（1．75cm）分别为BMP组（0．76cm）和对照组（0．25cm）的2倍和7倍。SMT组修复组织Ⅰ型胶原表达量为65．9％，明显少于BMP组（88．5％）和对照组（94．6％）；Ⅱ型胶原表达量（30．7％）多于BMP组（10．8％）和对照组（4．5％）。结论iNOS抑制剂SMT的应用能明显增加软骨修复组织中糖胺聚糖含量，并能明显增加Ⅱ型胶原表达，对于维持软骨表型和提高软骨修复质量有积极意义。

Impact on proteoglycan and collagen expression in rabbit articular cartilage treated with inducible nitric oxide synthase inhibitor

Objective To examine glycosaminoglycans contents and collagen expressions in repaired cartilages of rabbit knee joints treated with inducible nitric oxide synthase inhibitor COS SMT. Methods Twenty-four adult New Zealand white rabbits which full-thickness defects of cartilage were created in the bilateral trochlear groove were randomly divided into the control, BMP group and SMT group. Animals were killed at one-year postoperatively. Repaired cartilage sections were stained with safranin O and Sirius- Red. Glycosaminoglycans contents and collagen expressions were analyzed by Quantiment 500 system. With this system repaired tissues were assessed histomorphometrically for the following parameters： pereentage of safranin O stained area, collagen type- Ⅰ and type- Ⅱ stained area, cartilage thickness. Results One-year postoperatively,percentage of safranin O stained area of repair tissues in SMT group （89. 28% ） was more than in BMP group （36. 54% ） and the control （ 13.4% ）, as well as mean gray scale （ 134, 5 ） was more than in BMP group （56. 8 ） and the control （26. 4） too. The repaired cartilage thickness of SMT group （1.75 cm）was significant higher than BMP group（0. 76 cm）and the control（0. 25 cm）. Collagen type- Ⅰ expression of repair tissues in SMT group（65.9% ） was less than in BMP group（ 88. 5% ） and in the control （94. 6% ） ,and collagen type- Ⅱ in SMT group （30. 7% ） was more than in BMP group（ 10. 8% ） and the control（4. 5% ）. Conclusions NOS inhibitor SMT could increase glycosaminoglycans synthesis, as well as increase collagen type- Ⅱ expression, suggesting a role to play for NO in cartilage repair.