Age-related changes in sympathetic nervous activity of rats receiving vitamin E-deficient diet

To study the relationship between age-related stimulation of sympathetic nervous activity and vitamin E, excretion of urinary catecholamine and the contents of organ catecholamine were measured in rats receiving a vitamin E-deficient or control diet for 95 weeks. Rats exhibited about 95% hemolysis after 4 weeks on the vitamin E-deficient diet and this value remained the same for 95 weeks. alpha-Tocopherol in plasma was not detectable in the deficient diet-fed rats, and lipid peroxide concentrations in the plasma, liver and adrenal glands of rats receiving the vitamin E-deficient diet for 95 weeks were 3- to 30-fold higher than those of control rats. Urinary excretion of catecholamine (norepinephrine (NE), epinephrine (E) and dopamine (DA] increased with age. Excretion of NE in 24-h urine of rats receiving the vitamin E-deficient diet for 50 and 95 weeks was 2- to 3-fold higher than that of control rats, although no significant difference was observed at week 12. Contents of NE and E in the adrenal glands and of NE in the heart from the deficient rats were significantly lower than those of control rats at week 95. These results suggest that sympathetic nervous activity is enhanced in aged rats and that the sympathetic nervous activity in vitamin E-deficient rats is greater than in control rats.