Verhoeven N M, Schor D S, Roe C R, Wanders R J, Jakobs C
Department of Clinical Chemistry, Free University Hospital, Amsterdam, The Netherlands.
Biochim Biophys Acta. 1997 Oct 24;1361(3):281-6. doi: 10.1016/s0925-4439(97)00045-8.
We studied the alpha-oxidation of phytanic acid in human fibroblasts of controls and patients affected with classical Refsum disease, rhizomelic chondrodysplasia punctata, generalized peroxisomal disorders and peroxisomal bifunctional protein deficiency. Cultured fibroblasts were incubated with phytanic acid, after which medium and cells were collected separately. 2-Hydroxyphytanic acid and pristanic acid were measured in the medium and cells by stable isotope dilution gas chromatography mass spectrometry. In controls, 2-hydroxyphytanic acid and pristanic acid could be detected in the medium after incubation with phytanic acid, proving that alpha-oxidation of phytanic acid via 2-hydroxyphytanoyl-CoA to pristanic acid was active and intermediates were excreted into the medium. In cells from patients with a defective alpha-oxidation (Refsum disease, rhizomelic chondrodysplasia punctata and generalized peroxisomal disorders) 2-hydroxyphytanic acid and pristanic acid were low or not detectable, showing that in these disorders the hydroxylation of phytanoyl-CoA to 2-hydroxyphytanoyl-CoA is deficient. In cells with a peroxisomal beta-oxidation defect, 2-hydroxyphytanic acid and pristanic acid were formed in amounts comparable to those in the controls.
我们研究了植烷酸在对照人群以及患有经典型Refsum病、肢根型点状软骨发育不良、全身性过氧化物酶体疾病和过氧化物酶体双功能蛋白缺乏症患者的人成纤维细胞中的α-氧化作用。将培养的成纤维细胞与植烷酸一起孵育，之后分别收集培养基和细胞。通过稳定同位素稀释气相色谱-质谱法测定培养基和细胞中的2-羟基植烷酸和降植烷酸。在对照人群中，与植烷酸孵育后，培养基中可检测到2-羟基植烷酸和降植烷酸，证明通过2-羟基植烷酰辅酶A将植烷酸α-氧化为降植烷酸的过程是活跃的，且中间产物被排泄到培养基中。在α-氧化存在缺陷的患者（Refsum病、肢根型点状软骨发育不良和全身性过氧化物酶体疾病）的细胞中，2-羟基植烷酸和降植烷酸含量较低或无法检测到，表明在这些疾病中，植烷酰辅酶A羟基化为2-羟基植烷酰辅酶A的过程存在缺陷。在过氧化物酶体β-氧化存在缺陷的细胞中，2-羟基植烷酸和降植烷酸的生成量与对照人群相当。
