Ribaya J D, Gershoff S N
J Nutr. 1979 Jan;109(1):171-83. doi: 10.1093/jn/109.1.171.
Urinary endogenous oxalate was increased by feeding vitamin B6-deficient or control rats with 5.2% hydroxyproline, or 3% glycine plus 5.2% hydroxyproline. The activities of liver lactic dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G6PD) , malic enzyme (ME), and ATP citrate lyase were decreased in vitamin B6-DEFICIENT RATS, AND THEIR LIVEr G6PD was further decreased by the addition of glycine and hydroxyproline to their diets. Supplementing control diets with the two amino acids decreased the activities of rat liver LDH, G6PD, and ATP citrate lyase. The effects of glycine and hydroxyproline feeding on the enzymes studied did not appear related to alterations in insulin availability. Since in vitamin B6-deficient rats, there are increases in urinary levels of oxalic and glycolic acids, and glycine, and increases in tissue levels of glyoxylic acid and glycine, the effects of these metabolites on the activities of the above mentioned enzymes were measured. Oxalic acid inhibited the activities of LDH, G6PD, and ME. Glyoxylic acid inhibited LDH and ME, but not G6PD. Glycolic acid inhibited G6PD and ME, but not LDH. ATP citrate lyase was not affected by these substances. Glycine had no effect on the enzymes studied. Diets which increased oxalate excretion generally reduced or did not alter liver and kidney levels of oxalate, glycolate, and glyoxylate. However, the feeding of glycine and hydroxyproline increased kidney oxalate, and liver and kidney glyoxylate in vitamin B6-deficient rats.
通过给缺乏维生素B6的大鼠或对照大鼠喂食5.2%的羟脯氨酸，或3%的甘氨酸加5.2%的羟脯氨酸，可使尿内源性草酸盐增加。在缺乏维生素B6的大鼠中，肝脏乳酸脱氢酶（LDH）、葡萄糖-6-磷酸脱氢酶（G6PD）、苹果酸酶（ME）和ATP柠檬酸裂解酶的活性降低，并且在其饮食中添加甘氨酸和羟脯氨酸后，它们肝脏的G6PD活性进一步降低。在对照饮食中添加这两种氨基酸会降低大鼠肝脏LDH、G6PD和ATP柠檬酸裂解酶的活性。喂食甘氨酸和羟脯氨酸对所研究酶的影响似乎与胰岛素可用性的改变无关。由于在缺乏维生素B6的大鼠中，草酸、乙醇酸和甘氨酸的尿水平升高，乙醛酸和甘氨酸的组织水平升高，因此测定了这些代谢产物对上述酶活性的影响。草酸抑制LDH、G6PD和ME的活性。乙醛酸抑制LDH和ME，但不抑制G6PD。乙醇酸抑制G6PD和ME，但不抑制LDH。ATP柠檬酸裂解酶不受这些物质的影响。甘氨酸对所研究的酶没有影响。增加草酸盐排泄的饮食通常会降低或不改变肝脏和肾脏中草酸盐、乙醇酸盐和乙醛酸盐的水平。然而，在缺乏维生素B6的大鼠中，喂食甘氨酸和羟脯氨酸会增加肾脏草酸盐以及肝脏和肾脏中的乙醛酸盐。
