Experimental and Clinical Studies on the Activity of Human Serum Dopamine-β-Hydroxylase
1973 Volume 49 Issue 1 Pages 48-59,5
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1973 Volume 49 Issue 1 Pages 48-59,5
Dopamine-β-Hydroxylase is an enzyme which catalyzes dopamine to noradrenaline in final step of catecohlamine synthesis.
This study was undertaken to determine the human serum Dopaminel-β-Hydroxylase activity and examine effects of fusaric acid (5-butylpicolinic acid) on this enzyme activity in vitro and in vivo.
A sensitive method for measurement of the human serum Dopamine-β-Hydroxylase activity was established and it was important for the assay to adjust PH of reaction mixtures to PH 4.5.
The activity ranged from 39.95 to 176.00, mean was 82.31±33.11 (M. ±S.E.) in normal and that of patients with essential hypertension ranged from 31.11 to 234.97, mean was 109.87±57.23 (M.±S.E.) n moles/0.5 ml serum/15 min.
Fusaric acid showed 50% inhibition of the human serum Dopamine-β-Hydroxylase activity at concentration of 10-7 M in vitro and the activity in patients with essential hypertension was significantly decreased in a few days after the administration of fusaric acid 150 mg per day.
