VITAMIN-B-6 DEFICIENCY AFFECTS ANTIOXIDANT DEFENSES IN RAT-LIVER AND HEART

We have evalued the effects of a diet containing normal amounts of lip ids and a marginal content of vitamin B-6 on lipid peroxidation. Pyrid oxal phosphate concentrations of plasma and liver indicated that an in itial deficiency state was reached. Vitamin B-6 deficiency led to pero xidative stress: TEARS production was higher in the liver (+18.6%) and even more in the heart (+61%) of deficient rats as compared with cont rols. Furthermore, significant stimulation of glutathione-dependent en zymes occurred in both heart and liver of deficient rats: glutathione peroxidase activity increased in heart (+144%) and liver (+505%),gluta thione reductase increased in heart (+54.9%) and liver (+15.5%). No di fference in the total glutathione content of the organs of the two gro ups was observed. The reduced glutathione/oxidized glutathione ratio w as significantly lower in deficient rats. Although the activity of glu tathione-dependent enzymes was significantly greater in deficient rats than in controls, this stimulation was only partially able to counter act the peroxidative damage due to vitamin B-6 deficiency.