Christensen E
Department of Pediatrics, University of Copenhagen, Rigshospitalet, Denmark.
Clin Chim Acta. 1993 Oct 29;220(1):71-80. doi: 10.1016/0009-8981(93)90007-q.
A method described earlier for measuring glutaryl-CoA dehydrogenase activity in fibroblasts has been further developed. This assay uses the detritiation of [2,3,4-3H]glutaryl-CoA both with and without added artificial electron acceptors as a measure of glutaryl-CoA dehydrogenase activity. Fibroblasts from patients with glutaryl-CoA dehydrogenase deficiency, as determined by the 14CO2 release assay, showed very low detritiation of [2,3,4-3H]glutaryl-CoA without added artificial electron acceptor. Obligate heterozgotes for glutaryl-CoA dehydrogenase deficiency showed detritiation activity intermediate between homozygotes and normal individuals. Addition of an electron acceptor to the assay mixture had no influence on the activity in homozygotes for glutaryl-CoA dehydrogenase deficiency but more than doubled the detritiation activity in obligate heterozygotes and in normal individuals. No difference in detritiation activity could be detected between glutaryl-CoA dehydrogenase deficient patients with a high urinary excretion of glutaric acid and patients with almost no excretion of glutaric acid. In all glutaryl-CoA dehydrogenase deficient cell lines tested the loss of decarboxylation activity was also accompanied by a loss of dehydrogenation activity. The detritiation assay was equivalent to, or even better than, the 14CO2 release assay in distinguishing between homozygotes and heterozygotes for glutaryl-CoA dehydrogenase deficiency.
此前描述的一种用于测量成纤维细胞中戊二酰辅酶A脱氢酶活性的方法得到了进一步改进。该检测方法利用添加和不添加人工电子受体时[2,3,4-³H]戊二酰辅酶A的氚化作用来衡量戊二酰辅酶A脱氢酶的活性。通过¹⁴CO₂释放检测确定为戊二酰辅酶A脱氢酶缺乏症患者的成纤维细胞，在不添加人工电子受体时，[2,3,4-³H]戊二酰辅酶A的氚化作用非常低。戊二酰辅酶A脱氢酶缺乏症的 obligate 杂合子的氚化活性介于纯合子和正常个体之间。向检测混合物中添加电子受体对戊二酰辅酶A脱氢酶缺乏症纯合子的活性没有影响，但使 obligate 杂合子和正常个体的氚化活性增加了一倍多。在高尿排泄戊二酸的戊二酰辅酶A脱氢酶缺乏症患者和几乎不排泄戊二酸的患者之间，未检测到氚化活性的差异。在所有测试的戊二酰辅酶A脱氢酶缺乏细胞系中，脱羧活性的丧失也伴随着脱氢活性的丧失。在区分戊二酰辅酶A脱氢酶缺乏症的纯合子和杂合子时，氚化检测等同于甚至优于¹⁴CO₂释放检测。
