The effects of vitamin B-6 deficiency and hepatectomy on the synthesis of oxalate from glycolate in the rat.
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.
D000818:Animals; D006016:Glycolates / Q000378:metabolism*; D006038:Glyoxylates / Q000378:metabolism; D006498:Hepatectomy; D008099:Liver / Q000502:physiology*; D008297:Male; D010070:Oxalates / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains; D026681:Vitamin B 6 Deficiency / Q000378:metabolism*
D006016:Glycolates; D006038:Glyoxylates; D010070:Oxalates