Halcak L, Rendeková V, Pechán I, Kubaská M
Ustav lekárskej chémie, biochémie a klinickej biochémie Lekárskej fakulty Univerzity Komenského v Bratislave.
Bratisl Lek Listy. 1998 Jul;99(7):343-6.
Uric acid as the product of purine nucleotide degradation is an integrate component of blood plasma. This metabolite is considered to be one of the important naturally occurring antioxidants building up the antioxidation system of the organism. Creatine phosphate and carnitine are important substances participating in energy metabolism of the cells. Energy production is closely related to the level of reduction systems and thus also to the antiradical ability of the cell. By this mechanism could creatine phosphate and carnitine improve the antioxidative capacity of the cell.
In homogenates of rat brain cortex and myocardium was the production of oxygen radicals stimulated by mixture of Fe2+ ions and ascorbate. Oxygen radicals may induce lipid peroxidation by the means of the reaction with lipid structures. We tried to inhibit the process of lipid peroxidation by addition of uric acid, creatine phosphate and carnitine into the incubation medium. Intensity of lipoperoxidation was measured by detection of substances giving positive reaction with thiobarbituric acid (TBA) in homogenates of brain cortex and myocardium.
Uric acid in concentrations of 1 and 0.5 mmol.l-1 markedly inhibits the production of compounds reacting with TBA. This effect was not found in 0.05 mmol.l-1 concentration. Creatine phosphate and carnitine in 1 mmol.l-1 concentrations also decreased the value of lipid peroxides in homogenates of brain cortex, but their effect was lower than the effect of uric acid. This effect was not seen in myocardium homogenates.
尿酸作为嘌呤核苷酸降解的产物，是血浆的一个组成部分。这种代谢物被认为是构建机体抗氧化系统的重要天然抗氧化剂之一。磷酸肌酸和肉碱是参与细胞能量代谢的重要物质。能量产生与还原系统水平密切相关，因此也与细胞的抗自由基能力密切相关。通过这种机制，磷酸肌酸和肉碱可能会提高细胞的抗氧化能力。
在大鼠大脑皮层和心肌的匀浆中，用Fe2+离子和抗坏血酸的混合物刺激氧自由基的产生。氧自由基可通过与脂质结构反应诱导脂质过氧化。我们试图通过在孵育介质中添加尿酸、磷酸肌酸和肉碱来抑制脂质过氧化过程。通过检测大脑皮层和心肌匀浆中与硫代巴比妥酸（TBA）呈阳性反应的物质来测量脂质过氧化的强度。
浓度为1和0.5 mmol·l-1的尿酸显著抑制与TBA反应的化合物的产生。在0.05 mmol·l-1浓度下未发现这种作用。浓度为1 mmol·l-1的磷酸肌酸和肉碱也降低了大脑皮层匀浆中脂质过氧化物的值，但其作用低于尿酸。在心肌匀浆中未观察到这种作用。
