Effects of high ascorbic acid intake on the metabolism of catecholamines in the rat

The effect of high dietary ascorbic acid intake on the homeostasis of ascorbic acid and on the metabolism of catecholamine was studied in rats. In order to eliminate changes in serum levels due to stress, blood was obtained without anesthesia through implanted cannulas. Rats with a high intake of ascorbic acid (20 g/kg diet, for 7-9 weeks) had significantly higher levels of ascorbic acid in serum (83%), liver (28%), kidney (47%) and superior cervical ganglia (43%). The values were slightly, but not significantly higher in adrenal gland, brain and interscapular brown adipose tissue. However, no significant differences were observed in the levels of noradrenalin, adrenalin and dopamine in any of the tissues analyzed. Dopamine beta-hydroxylase activity was also unchanged. There was thus no evidence of an effect of high dietary intakes of ascorbic acid on the metabolism of catecholamines in the intact rat.