[Blood phenolsulfotransferase and monoamine oxidase-B activity in essential arterial hypertension].
Circulating phenolsulfotransferase M and P and monoamine oxidase activities were determined in 18 untreated essential hypertensive patients and in 35 normotensive healthy controls. Phenolsulfotransferase M is involved in the sulfoconjugation of catecholamines and their metabolites while PST P preferentially sulfates phenolic substrates. After lysis of whole blood, enzymatic activities were determined by radioenzymatic techniques using as substrates 3-methoxy-4-phenoxyphenylglycol for PST M, phenol for PST P and [14C] beta-phenylethylamine for MAO. Blood MAO activity measured by this method is fully accounted for by platelet MAO-B activity. Concerning blood PST activities, no significant difference was found in hypertensive patients compared to normotensive controls (PST M: 1.69 +/- 0.17 versus 1.66 +/- 0.08 nmoles of MHPG-sulfate/ml of blood/hour; PST P: 0.36 +/- 0.05 versus 0.27 +/- 0.04 nmoles of phenol-sulfate/ml of blood/hour). MAO activity was higher in women than in men. Significantly lower MAO B activities were observed in hypertensive patients both in men (19.25 +/- 2.20, n = 8 versus 24.35 +/- 2.22, n = 14, desaminated beta-phenyl-ethylamine/10(9) platelets/hour, x +/- SEM, p less than 0.05) and in women (23.92 +/- 2.74, n = 10 versus 35.76 +/- 2.35, n = 21, p less than 0.01) when compared to normotensive controls of the same sex. Recent in vitro studies have suggested that a reduction in platelet MAO B activity may be induced by an alteration in the phospholipidic and/or calcium environment of the enzyme. Low MAO activity in other tissues such as liver or vascular endothelium could contribute to the high sympathetic tone observed in these patients.
D015239:Arylsulfotransferase; D005260:Female; D006801:Humans; D006973:Hypertension / Q000201:enzymology*; D008297:Male; D008995:Monoamine Oxidase / Q000097:blood*; D012737:Sex Factors; D013466:Sulfurtransferases / Q000097:blood*
D008995:Monoamine Oxidase; D013466:Sulfurtransferases; D015239:Arylsulfotransferase
Activités phénolsulfotransférases et monoamine oxydase-B sanguines dans l'hypertension artérielle essentielle.