Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600, Porto Alegre, RS, 90035-003, Brazil.
Neurotox Res. 2017 Nov;32(4):575-584. doi: 10.1007/s12640-017-9762-5. Epub 2017 Jun 13.
Maple syrup urine disease is an autosomal metabolic disease caused by a deficiency of branched-chain α-keto acid dehydrogenase complex activity. In this disease occur the accumulation of the branched-chain amino acids leucine, isoleucine, and valine and their corresponding branched-chain α-keto acids in the tissues and body fluids. The affected patients may present psychomotor development delay and mental retardation. The pathophysiology of maple syrup urine disease is not entirely understood, but leucine seems to be the primary neurotoxic metabolite. Creatine and pyruvate are energetics and antioxidants substances. In this study, we investigated the effects of leucine administration and co-administration of creatine plus pyruvate on several parameters of oxidative stress and phosphoryl transfer network in cerebral cortex and hippocampus of Wistar rats treated from the 8th to the 21st postpartum day. Leucine induced oxidative stress and diminished the activities of pyruvate kinase, adenylate kinase, cytosolic and mitochondrial creatine kinase. Co-administration of creatine plus pyruvate prevented the alterations provoked by leucine administration on the oxidative stress and the enzymes of phosphoryltransfer network. These results indicate that chronic administration of leucine may stimulate oxidative stress and alters the enzymes of phosphoryltransfer network in the cerebral cortex and hippocampus of the rats. It is possible that these effects may contribute, along with other mechanisms, to the neurological dysfunction found in patients affected by maple syrup urine disease. In this case, it is possible that creatine plus pyruvate supplementation could benefit to the patients.
枫糖尿症是一种常染色体隐性遗传的支链氨基酸代谢病,由于支链α-酮酸脱氢酶复合体的活性缺乏引起。在这种疾病中,分支链氨基酸亮氨酸、异亮氨酸和缬氨酸及其相应的分支链α-酮酸在组织和体液中积累。受影响的患者可能表现出精神运动发育迟缓、智力低下。枫糖尿症的病理生理学尚未完全了解,但亮氨酸似乎是主要的神经毒性代谢物。肌酸和丙酮酸是能量和抗氧化物质。在这项研究中,我们研究了亮氨酸给药和肌酸加丙酮酸共同给药对从第 8 天到第 21 天产后接受治疗的 Wistar 大鼠大脑皮层和海马中氧化应激和磷酸转移网络几个参数的影响。亮氨酸诱导氧化应激,降低丙酮酸激酶、腺苷酸激酶、细胞质和线粒体肌酸激酶的活性。肌酸加丙酮酸的共同给药可预防亮氨酸给药引起的氧化应激和磷酸转移网络酶的改变。这些结果表明,亮氨酸的慢性给药可能会刺激氧化应激,并改变大鼠大脑皮层和海马中的磷酸转移网络酶。这些影响可能与其他机制一起,导致枫糖尿症患者的神经功能障碍。在这种情况下,肌酸加丙酮酸的补充可能对患者有益。