Ponzone A, Guardamagna O, Spada M, Ponzone R, Sartore M, Kierat L, Heizmann C W, Blau N
Department of Pediatric Clinic, University of Torino, Italy.
Clin Chim Acta. 1993 Jul 16;216(1-2):63-71. doi: 10.1016/0009-8981(93)90139-u.
The relationship between blood phenylalanine concentrations and serum and erythrocyte biopterin and neopterin concentrations was investigated in 20 phenylketonuric patients with different dietary compliance. At serum phenylalanine concentrations ranging from 43 to 1004 mumol/l, a good correlation was found with serum biopterin (r = 0.76, P < 0.001) and with red blood cell biopterin (r = 0.62, P < 0.001). A similar correlation was found between serum neopterin and phenylalanine (r = 0.60, P < 0.001). The correlation between red blood cell neopterin and serum phenylalanine was less evident, however (r = 0.47, P < 0.005). After oral loading with phenylalanine (100 mg/kg body weight), serum and red blood cell biopterin concentrations increased in patients with classical phenylketonuria as well as in one patient with dihydropteridine reductase deficiency in response to the induced acute hyperphenylalaninemia. One patient suffering from 6-pyruvoyl tetrahydropterin synthase deficiency was loaded orally with tetrahydrobiopterin (20 mg/kg body weight). The kinetics of administered cofactor confirmed its rapid absorption, with early increase of serum concentrations followed by its transport into the red blood cells. The half-life of biopterin was approximately 7 h in serum and 15 h in red blood cells. Because both values are less than the half-life of phenylalanine (20-30 h) in serum, biopterin measurement offers no advantage in monitoring dietary control in hyperphenylalaninemic patients.
在20例饮食依从性不同的苯丙酮尿症患者中，研究了血液苯丙氨酸浓度与血清及红细胞生物蝶呤和新蝶呤浓度之间的关系。在血清苯丙氨酸浓度为43至1004μmol/L的范围内，发现与血清生物蝶呤（r = 0.76，P < 0.001）和红细胞生物蝶呤（r = 0.62，P < 0.001）有良好的相关性。血清新蝶呤与苯丙氨酸之间也发现了类似的相关性（r = 0.60，P < 0.001）。然而，红细胞新蝶呤与血清苯丙氨酸之间的相关性不太明显（r = 0.47，P < 0.005）。口服苯丙氨酸（100mg/kg体重）后，经典型苯丙酮尿症患者以及1例二氢蝶呤还原酶缺乏症患者的血清和红细胞生物蝶呤浓度因诱导的急性高苯丙氨酸血症而升高。1例患有6-丙酮酰四氢蝶呤合酶缺乏症的患者口服了四氢生物蝶呤（20mg/kg体重）。所给予辅因子的动力学证实了其快速吸收，血清浓度早期升高，随后转运至红细胞。生物蝶呤在血清中的半衰期约为7小时，在红细胞中为15小时。由于这两个值均小于血清中苯丙氨酸的半衰期（20 - 30小时），因此生物蝶呤测量在监测高苯丙氨酸血症患者的饮食控制方面没有优势。
