Shaposhnikova A M, Skachkov M M, Babitskiĭ G Ia
Vopr Med Khim. 1977 Sep-Oct;23(5):597-601.
Phenylalanine-4-hydroxylase activity was studied in liver tissue, obtained by biopsy from 5 patients with viral hepatitis and from 8 persons without parthological alterations of liver. The enzymatic activity was estimated by formation of 14C-tyrosine in presence and in absence of added cofactor 2-amine-4-hydroxy-6,7-dimethyltetrahydropteridine. Without addition of the cofactor the phenylalanine hydroxylase activity was of the same order of magnitude in liver tissue of the patients and of healthy persons. In presence of the cofactor the enzyme activity in liver of the patients with the hepatitis of moderate severity constituted 44% of the activity found in the control group. The rate of phenylalanine hydroxylation was 0.19 with 10-2 min-1 in patients with hepatitis and 0.5 with 10-2 min-1--in the control group. In severe and moderate forms of viral hepatitis the impairment of phenylalanine metabolism was due to decrease in the activity of phenylalanine-4-hydroxylase in liver tissue.
对5例病毒性肝炎患者及8例肝脏无病理改变者经活检获取的肝组织中的苯丙氨酸-4-羟化酶活性进行了研究。通过在添加和不添加辅因子2-氨基-4-羟基-6,7-二甲基四氢蝶啶的情况下14C-酪氨酸的生成来评估酶活性。不添加辅因子时，患者肝组织和健康人肝组织中的苯丙氨酸羟化酶活性处于同一数量级。在添加辅因子的情况下，中度严重肝炎患者肝脏中的酶活性占对照组中所发现活性的44%。肝炎患者中苯丙氨酸羟化速率为0.19×10⁻² min⁻¹，而对照组中为0.5×10⁻² min⁻¹。在重度和中度病毒性肝炎中，苯丙氨酸代谢受损是由于肝组织中苯丙氨酸-4-羟化酶活性降低所致。
