Effect of vitamin B6 deficiency on glyoxylate metabolism in rats with or without glyoxylate overload.
We examined the effect of vitamin B6 deficiency on glyoxylate metabolism and hepatic alanine: glyoxylate aminotransferase (AGT) activity in rats with normal or high glyoxylate intake. Male rats were divided into four groups: a control group, a vitamin B6-free diet group, a glyoxylate water group, and a vitamin B6-free diet + glyoxylate water group. Each group was given special diet (control or vitamin B6-deficient diet) and drinking water (plain or 0.5% glyoxylate water) for 4 weeks, after which biochemical parameters and hepatic AGT mRNA level were measured. Compared with control rats, the urinary oxalate/creatinine ratio was higher in each of the other 3 groups. The urinary glycolate/creatinine ratio was also higher in the vitamin B6-free diet group and the vitamin B6-free diet + glyoxylate water group than the control group, while the urinary glycine/creatinine and citrate/creatinine ratio was lower in both groups. The hepatic AGT mRNA level was reduced in the vitamin B6-free diet group, but was increased in the glyoxylate water group than the control group. These results suggest that vitamin B6 is necessary for glyoxylate metabolism as a coenzyme of AGT. Especially in the presence of a high glyoxylate intake, vitamin B6 deficiency leads to severe hyperoxaluria and hypocituria.
Nishijima
Saori
S
Division of Urology, Department of Organ-oriented Medicine, Faculty of Medicine, University of the Ryukyus, Okinawa, Japan. k998739@med.u-ryukyu.ac.jp
Sugaya
Kimio
K
Hokama
Sanehiro
S
Oshiro
Yoshinori
Y
Uchida
Atsushi
A
Morozumi
Makoto
M
Ogawa
Yoshihide
Y
D000409:Alanine / Q000378:metabolism; D000410:Alanine Transaminase / Q000097:blood / Q000652:urine; D000818:Animals; D006038:Glyoxylates / Q000378:metabolism*; D006959:Hyperoxaluria / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D000637:Transaminases / Q000097:blood / Q000652:urine; D026681:Vitamin B 6 Deficiency / Q000473:pathology*; D014867:Water / Q000378:metabolism
D006038:Glyoxylates; D012333:RNA, Messenger; D014867:Water; D000637:Transaminases; C023067:glyoxylate aminotransferase; D000410:Alanine Transaminase; D000409:Alanine