Varalakshmi P, Richardson K E
Biochim Biophys Acta. 1983 May 4;757(1):1-7. doi: 10.1016/0304-4165(83)90145-9.
The interrelationship between vitamin B-6 deficiency, liver and extrahepatic tissues with respect to oxalate biosynthesis from [14C1]glycolate in the rat has been investigated. Separate groups of vitamin B-6 deficient and control rats were subjected to total hepatectomy and the metabolism of injected [14C1]glycolate was followed by measuring the respired 14CO2 and analyzing the urine and blood for radioactive metabolites. Vitamin B-6 deficient and control rats were subjected to sham hepatectomies and used as controls. Vitamin B-6 deficient rats showed elevated urinary oxalate compared to controls. Hepatectomy reduced [14C]oxalate excretion and eliminated the B-6 effect. Respiratory 14CO2 was significantly lowered in hepatectomized rats and vitamin B-6 deficiency enhanced the reduction. A difference in oxalate metabolism between normal and vitamin B-6 deficient rat kidneys and possibly other tissues is indicated. The results suggest that the influence of vitamin B-6 on oxalate metabolism is mediated mainly through the liver and supports earlier observations that liver, which contains two oxalate synthesizing enzymes, glycolic acid oxidase and glycolic acid dehydrogenase, is a primary site for the synthesis of oxalate from glycolate.
研究了大鼠体内维生素B-6缺乏、肝脏及肝外组织在由[¹⁴C₁]乙醇酸合成草酸盐方面的相互关系。将单独分组的维生素B-6缺乏大鼠和对照大鼠进行全肝切除术，通过测量呼出的¹⁴CO₂以及分析尿液和血液中的放射性代谢物来追踪注射的[¹⁴C₁]乙醇酸的代谢情况。对维生素B-6缺乏大鼠和对照大鼠进行假肝切除术并用作对照。与对照相比，维生素B-6缺乏大鼠的尿草酸盐升高。肝切除术减少了[¹⁴C]草酸盐的排泄并消除了维生素B-6的影响。肝切除大鼠的呼吸¹⁴CO₂显著降低，维生素B-6缺乏加剧了这种降低。这表明正常大鼠和维生素B-6缺乏大鼠的肾脏以及可能的其他组织在草酸盐代谢方面存在差异。结果表明，维生素B-6对草酸盐代谢的影响主要通过肝脏介导，这支持了早期的观察结果，即肝脏含有两种草酸盐合成酶，乙醇酸氧化酶和乙醇酸脱氢酶，是由乙醇酸合成草酸盐的主要部位。
