Suleiman S A, Jones G L, Singh H, Labrecque D R
Biochim Biophys Acta. 1980 Jan 3;627(1):17-22. doi: 10.1016/0304-4165(80)90118-x.
The effect of 2/3 hepatectomy in the adult rat on the specific and total activities of two lysosomal endopeptidases, cathepsins B1 and D, has been examined. The specific activity of both enzymes fell rapidly following hepatectomy when compared to paired, sham-operated controls. When changes in total protein were compared to changes in cathepsins B1 and D, all three decreased in a parallel fashion for the first 18 h. At 24 h, total liver protein increased rapidly while cathepsins B1 and D continued to decrease. Cathepsin B1 fell to a level of 12% of non-operated control levels at 36 h, while total protein was already back to 40% of control levels. In contrast to the decreases in the activities of the cathepsins, there was an increase in the activities of lactate dehydrogenase and malate dehydrogenase during the first two days of regeneration. The clear lag in replacement of the cathepsins relative to other liver proteins following partial hepatectomy suggests that cathepsin activity is selectively controlled and that lowering the levels of cathepsins B1 and D may play an important role in the decreased degradation of protein seen during the early phases of liver regeneration.
研究了成年大鼠2/3肝切除对两种溶酶体组织蛋白酶B1和D的比活性及总活性的影响。与配对的假手术对照组相比，肝切除后两种酶的比活性迅速下降。当将总蛋白的变化与组织蛋白酶B1和D的变化进行比较时，在最初18小时内，三者均呈平行下降。在24小时时，肝脏总蛋白迅速增加，而组织蛋白酶B1和D继续下降。组织蛋白酶B1在36小时时降至未手术对照水平的12%，而总蛋白已恢复至对照水平的40%。与组织蛋白酶活性下降相反，在再生的前两天，乳酸脱氢酶和苹果酸脱氢酶的活性增加。部分肝切除后，组织蛋白酶相对于其他肝脏蛋白的替代明显滞后，这表明组织蛋白酶活性受到选择性控制，降低组织蛋白酶B1和D的水平可能在肝脏再生早期蛋白质降解减少中起重要作用。
