INCREASED MEMBRANE RATIOS OF METABOLITE TO PRECURSOR FATTY-ACID IN ESSENTIAL-HYPERTENSION

Desaturase enzymes are responsible for the conversion of essential fat ty acids to the longer-chain eicosanoid precursors. These enzymes requ ire zinc as an essential cofactor, and the following ratios-C20:4/C18: 2, C20:5/C18:3, and C22:6/C20:5-are considered indexes of their activi ty. We analyzed these parameters in plasma and erythrocyte membranes o f 105 essential hypertensive patients, 20 white coat hypertensive pati ents, and 100 age-matched normotensive control subjects. Dietary analy sis excluded significant quantitative and qualitative differences in f atty acid dietary intake between essential hypertensive patients and n ormotensive control subjects. Zinc levels and C20:4/C18:2, C20:5/C18:3 , and C22:6/C20:5 ratios were significantly higher in essential hypert ensive patients than control subjects, whereas white coat hypertensive patients showed intermediate values for all these parameters. These d ata provide evidence for an alteration in fatty acid metabolism of ess ential hypertensive patients, consistent with increased activity of de saturase enzymes. The consequent greater bioavailability of eicosanoid precursors, and in particular of arachidonic acid, could affect sever al vascular functions and have a bearing on the pathogenesis or compli cations of hypertension.