Burns R A, Buttery P J
Arch Biochem Biophys. 1984 Sep;233(2):507-14. doi: 10.1016/0003-9861(84)90474-0.
The metabolism of some purine compounds to urate and their effects on de novo urate synthesis in chicken hepatocytes were investigated. The purines, listed in descending order of rates of catabolism to urate, were hypoxanthine, xanthine, inosine, guanosine, guanine, IMP, GMP, adenosine, AMP, and adenine. During a 1-h incubation period, conversion to urate accounted for more than 80% of the total quantities of guanine, guanosine, and inosine metabolized, but only 42% of the adenosine and 23% of the adenine metabolism. Adenine, adenosine, and AMP inhibited de novo urate synthesis [( 14C]formate incorporation into urate), whereas the other purines, especially guanine, guanosine, and GMP, stimulated de novo urate synthesis. When hepatocytes were incubated with glutamine and adenosine, AMP, guanine, guanosine, or GMP, the rates of de novo urate synthesis were lower than the additive effects of glutamine and the purine in separate incubations. Increasing phosphate concentrations had no effect on urate synthesis in the absence of added purines but, in combination with adenosine, AMP, guanosine, or GMP, increased urate synthesis. These results indicate that the ratio of adenine to guanine nucleotides and the interaction between substrates and purine nucleotides are involved in the regulation of urate biosynthesis in chicken liver.
研究了一些嘌呤化合物在鸡肝细胞中代谢生成尿酸的过程及其对尿酸从头合成的影响。按照分解代谢生成尿酸的速率从高到低排列，这些嘌呤依次为次黄嘌呤、黄嘌呤、肌苷、鸟苷、鸟嘌呤、肌苷酸（IMP）、鸟苷酸（GMP）、腺苷、腺苷酸（AMP）和腺嘌呤。在1小时的孵育期内，鸟嘌呤、鸟苷和肌苷代谢总量中转化为尿酸的比例超过80%，但腺苷的这一比例仅为42%，腺嘌呤则为23%。腺嘌呤、腺苷和AMP抑制尿酸的从头合成[尿酸中（14C）甲酸的掺入]，而其他嘌呤，尤其是鸟嘌呤、鸟苷和GMP，则刺激尿酸的从头合成。当肝细胞与谷氨酰胺和腺苷、AMP、鸟嘌呤、鸟苷或GMP一起孵育时，尿酸从头合成的速率低于谷氨酰胺和嘌呤单独孵育时的加和效应。在不添加嘌呤的情况下，增加磷酸盐浓度对尿酸合成没有影响，但与腺苷、AMP、鸟苷或GMP一起时，则会增加尿酸合成。这些结果表明，腺嘌呤与鸟嘌呤核苷酸的比例以及底物与嘌呤核苷酸之间的相互作用参与了鸡肝脏中尿酸生物合成的调节。
