Rindi G, Casirola D, Poggi V, De Vizia B, Patrini C, Laforenza U
Institute of Human Physiology, University of Pavia, Italy.
J Inherit Metab Dis. 1992;15(2):231-42. doi: 10.1007/BF01799637.
A 9-year study of thiamine metabolism and cellular transport was performed in two patients with thiamine-responsive megaloblastic anaemia associated with diabetes mellitus and sensorineural deafness, in their relatives, and in age-matched controls from the same area. The ratios between the content of thiamine and that of its phosphoesters in erythrocytes were within the normal range, whereas the absolute values of thiamine and thiamine compounds were reduced by about 40% as compared to controls. Thiamine pyrophosphokinase activity was about 30% lower than in controls. Thiamine treatment restored the levels of thiamine and thiamine compounds to normal values, whereas kinase was unaffected. Both the saturable (specific, predominant at low, less than 2 mumol/L, physiological concentrations of thiamine) and the non-saturable component of thiamine transport were investigated. Erythrocytes and ghosts from patients exhibited no saturable component, this abnormality being specific for the patients and not shared by their parents. It is concluded that the cells from thiamine-responsive megaloblastic anaemia patients contain low levels of thiamine compounds, probably due to their inability to take up and retain physiological concentrations of thiamine, as a result of the lack of the saturable, specific component of transport and reduced thiamine pyrophosphokinase.
对两名患有与糖尿病和感音神经性耳聋相关的硫胺素反应性巨幼细胞贫血的患者、他们的亲属以及来自同一地区年龄匹配的对照者进行了一项为期9年的硫胺素代谢和细胞转运研究。红细胞中硫胺素及其磷酸酯含量的比值在正常范围内，而硫胺素和硫胺素化合物的绝对值与对照相比降低了约40%。硫胺素焦磷酸激酶活性比对照低约30%。硫胺素治疗可使硫胺素和硫胺素化合物的水平恢复到正常值，而激酶不受影响。对硫胺素转运的可饱和成分（特异性的，在低生理浓度即低于2 μmol/L的硫胺素时占主导）和非可饱和成分均进行了研究。患者的红细胞和红细胞影未表现出可饱和成分，这种异常是患者特有的，其父母未出现。结论是，硫胺素反应性巨幼细胞贫血患者的细胞中硫胺素化合物水平较低，这可能是由于缺乏可饱和的特异性转运成分以及硫胺素焦磷酸激酶降低，导致细胞无法摄取和保留生理浓度的硫胺素。
