Vitamin B6 deficiency affects antioxidant defences in rat liver and heart.
We have evaluated the effects of a diet containing normal amounts of lipids and a marginal content of vitamin B6 on lipid peroxidation. Pyridoxal phosphate concentrations of plasma and liver indicated that an initial deficiency state was reached. Vitamin B6 deficiency led to peroxidative stress: TBARS production was higher in the liver (+18.6%) and even more in the heart (+61%) of deficient rats as compared with controls. Furthermore, significant stimulation of glutathione-dependent enzymes occurred in both heart and liver of deficient rats: glutathione peroxidase activity increased in heart (+144%) and liver (+505%); glutathione reductase increased in heart (+54.9%) and liver (+15.5%). No difference in the total glutathione content of the organs of the two groups was observed. The reduced glutathione/oxidized glutathione ratio was significantly lower in deficient rats. Although the activity of glutathione-dependent enzymes was significantly greater in deficient rats than in controls, this stimulation was only partially able to counteract the peroxidative damage due to vitamin B6 deficiency.
Cabrini
L
L
Department of Biochemistry G. Moruzzi, University of Bologna, Italy.
Bergami
R
R
Fiorentini
D
D
Marchetti
M
M
Landi
L
L
Tolomelli
B
B
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D015227:Lipid Peroxidation; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D026681:Vitamin B 6 Deficiency / Q000378:metabolism*; D014810:Vitamin E / Q000378:metabolism
D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005978:Glutathione