van Osch G J, van der Kraan P M, van den Berg W B
Department of Rheumatology, University Hospital Nijmegen, The Netherlands.
J Rheumatol. 1994 Jun;21(6):1107-12.
We studied whether inhibition of proteoglycan synthesis on different locations occurs according to a regular stimulus unrelated pattern or whether the response of cartilage is stimulus dependent.
Proteoglycan synthesis in murine knee joint cartilage was measured after in vitro and in vivo exposure to 3 metabolic stimuli, iodoacetate, papain and interleukin 1 alpha (IL-1 alpha). Knee joint cartilage was divided in 4 specific areas: the central and peripheral patella and medial and lateral tibial plateau.
The effect on proteoglycan synthesis in cartilage from these locations was similar in the in vitro and the in vivo experiments. Papain evoked more inhibition of the proteoglycan synthesis in tibial cartilage than in patellar cartilage. In contrast, iodoacetate caused more inhibition in patellar than in tibial cartilage. The central part of the patella was more vulnerable than the peripheral part of IL-1 alpha and iodoacetate, and both parts were equally sensitive to papain. Differences in sensitivity between central medial and central lateral tibial plateau were found only with iodoacetate, which inhibited proteoglycan synthesis medially more than laterally.
Our results indicate that inhibition of proteoglycan synthesis in specific areas of the knee joint is stimulus dependent.
我们研究了蛋白聚糖合成在不同位置的抑制是否按照与刺激无关的规律模式发生，或者软骨的反应是否依赖于刺激。
在体外和体内分别将小鼠膝关节软骨暴露于三种代谢刺激物碘乙酸盐、木瓜蛋白酶和白细胞介素1α（IL-1α）后，测量蛋白聚糖的合成。膝关节软骨被分为四个特定区域：髌骨中央和周边以及胫骨平台内侧和外侧。
在体外和体内实验中，这些位置的软骨对蛋白聚糖合成的影响相似。木瓜蛋白酶对胫骨软骨中蛋白聚糖合成的抑制作用比对髌骨软骨的更强。相反，碘乙酸盐对髌骨软骨的抑制作用比对胫骨软骨的更强。髌骨中央部分比周边部分对IL-1α和碘乙酸盐更敏感，且两部分对木瓜蛋白酶的敏感性相同。仅在碘乙酸盐作用下，发现胫骨平台中央内侧和中央外侧的敏感性存在差异，内侧对蛋白聚糖合成的抑制作用比外侧更强。
我们的结果表明，膝关节特定区域蛋白聚糖合成的抑制是依赖于刺激的。
