Quastel M, Harrison R, Cicardi M, Alper C A, Rosen F S
J Clin Invest. 1983 Apr;71(4):1041-6. doi: 10.1172/jci110831.
The metabolism of normal C1 inhibitor and two dysfunctional C1 inhibitors (Ta and WeI) was studied in 10 normal subjects and 8 patients with hereditary angioneurotic edema (HANE), 4 with low antigen concentration (type 1) and 4 with dysfunctional protein (type 2). The fractional catabolic rate of the normal C1 inhibitor in normal subjects was 0.025 of the plasma pool/hour, whereas in HANE subjects it was significantly elevated at 0.035 of the plasma pool/hour. The synthesis of normal C1 inhibitor was decreased in patients with type 1 HANE (0.087 mg/ kg per h compared with 0.218 mg/kg per h). The fractional catabolic rate of dysfunctional protein WeI was similar to normal and showed a slightly accelerated catabolism in patients with HANE, whereas the dysfunctional protein Ta had a strikingly decreased fractional catabolic rate in normals and subjects with HANE. The present study is compatible with reduced C1 inhibitor synthesis in patients with type 1 HANE consistent with a single functional C1 inhibitor gene. The lower than anticipated levels of C1 inhibitor in HANE type 1 appears to result from (a) the single functional gene and (b) increased catabolism of the protein, perhaps related to activation of C1 or other proteases.
在10名正常受试者和8名遗传性血管性水肿（HANE）患者中研究了正常C1抑制因子和两种功能失调的C1抑制因子（Ta和WeI）的代谢情况，其中4名患者抗原浓度低（1型），4名患者蛋白功能失调（2型）。正常受试者中正常C1抑制因子的血浆池分解代谢率为每小时0.025，而在HANE患者中显著升高，为每小时0.035血浆池。1型HANE患者中正常C1抑制因子的合成减少（每小时0.087毫克/千克，而正常人为每小时0.218毫克/千克）。功能失调蛋白WeI的血浆池分解代谢率与正常情况相似，且在HANE患者中分解代谢略有加速，而功能失调蛋白Ta在正常人和HANE患者中的血浆池分解代谢率显著降低。本研究结果与1型HANE患者中C1抑制因子合成减少一致，提示存在单一功能性C1抑制因子基因。1型HANE患者中C1抑制因子水平低于预期，可能是由于（a）单一功能基因，以及（b）蛋白分解代谢增加，这可能与C1或其他蛋白酶的激活有关。
