Renin-sodium profile and renal prostaglandins in the pathogenesis of systemic arterial hypertension in blacks.
Thirteen black women with systemic (essential) arterial hypertension, age-matched with normotensives, were examined during two protocols inducing sodium depletion and sodium loading respectively. Changes in plasma renin activity (PRA), urinary aldosterone values and prostaglandin E2 (PGE2) and F2a (PGF2a) excretion were simultaneously assessed. Renin profiles, obtained by the plotting of PRA against the urinary excretion of sodium, showed a 62% prevalence of low-renin hypertension, the remaining 38% of the patients having normal-renin hypertension. At basal level the hypertensives had suppressed renal synthesis of vasodilator PGE2 and a non-significant increase in venopressor PGF2a. This was reflected in the significant 32% decrease in the PGE2/PGF2a ratio. This finding was in keeping with their low-renin hypertension. During sodium depletion PG excretion was increased in both normotensive and hypertensive groups. The opposite effect was found during sodium loading. The results of this study do not support a natriuretic role for renal PGE2, but do support the hypothesis that there is decreased renal vasodepressor PGE2 synthesis in black hypertensive patients.
Somova
L
L
Department of Human Physiology and Physiological Chemistry, University of Durban-Westville.
Mufunda
J
J
D000328:Adult; D000450:Aldosterone / Q000652:urine; D044383:Black People; D005260:Female; D006801:Humans; D006973:Hypertension / Q000235:genetics / Q000503:physiopathology*; D007668:Kidney / Q000503:physiopathology*; D011188:Potassium / Q000652:urine; D011453:Prostaglandins / Q000378:metabolism / Q000502:physiology* / Q000652:urine; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System / Q000502:physiology*; D012964:Sodium / Q000652:urine*
D011453:Prostaglandins; D000450:Aldosterone; D012964:Sodium; D012083:Renin; D011188:Potassium