Boussidan F, Nahir A M
H. Schussheim Rheumatology Research Laboratory, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa.
J Exp Pathol (Oxford). 1990 Jun;71(3):395-402.
The depletion of proteoglycans (PGs), induced by a single intravenous injection of papain, is a useful model for studying the response of chondrocytes in vivo to injury. The present study concentrated on the activity of enzymes related to the synthesis of PGs, either directly, with uridine diphosphoglucose dehydrogenase (UDPGD), or indirectly, through the general oxidative metabolism of the chondrocytes. Most of the enzymes showed diminished activity on day 2; in some, there was little change in activity, whereas in others there was marked increase in activity over the following days. Thus, on day 9 the activities of glucose-6-phosphate dehydrogenase and of glyceraldehyde-3-phosphate dehydrogenase were twice the original (day 0) values, and those of succinate dehydrogenase and of UDPGD were one and a half times greater than the original activities. Such increased enzymatic activity preceded the increase in PG content, which by day 14 reached up to 80% of the initial value. Both the increased activity and the replenishment of the PG content were inhibited when hydrocortisone (10 mg/kg) was injected.
单次静脉注射木瓜蛋白酶诱导的蛋白聚糖（PGs）耗竭，是研究软骨细胞在体内对损伤反应的有用模型。本研究集中于与PGs合成相关的酶的活性，这些酶要么直接与尿苷二磷酸葡萄糖脱氢酶（UDPGD）有关，要么通过软骨细胞的一般氧化代谢间接相关。大多数酶在第2天活性降低；有些酶活性几乎没有变化，而另一些酶在接下来的几天里活性显著增加。因此，在第9天，葡萄糖-6-磷酸脱氢酶和甘油醛-3-磷酸脱氢酶的活性是初始值（第0天）的两倍，琥珀酸脱氢酶和UDPGD的活性比初始活性高1.5倍。这种酶活性的增加先于PG含量的增加，到第14天PG含量达到初始值的80%。当注射氢化可的松（10 mg/kg）时，酶活性的增加和PG含量的补充均受到抑制。
