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Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Evidence is presented demonstrating the role of prostaglandins in salt metabolism and on peripheral vasodilation. A number of animal studies and observations in human hypertensive subjects suggest that the prostaglandin system plays a role in the pathogenesis of hypertension. The most striking and consistent finding over many decades of investigation is the relationship between dietary salt intake and the development of hypertension. Only a small percentage of any population develops hypertension. It is suggested that those people whose kidneys have an abnormal salt-handling capacity develop hypertension when challenged by a chronic high-salt intake. The salutary effects of diuretics or low-salt diet support this concept. Hypertension then is an expression of a renal abnormality. Prostaglandins, one of the renal salt regulating factors of the kidney, amy be involved in this abnormality. Whether there is a defect in the matabolic pathways or an unresponsiveness to normal stimuli of prostaglandins has not been determined. The use of prostaglandins in the treatment of hypertension is being explored. The demonstration that PGA1 can effectively lower blood pressure and reverse hypertensive emergencies indicates that prostaglandins probably have a broader, still unidentified role in the overall management of essential hypertension.
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PMID:Prostaglandins and hypertension. 35 95

Prostaglandins A1, B1, E2, Falpha and PRA have been measured by radioimmunoassay in peripheral or renal venous blood of different groups of hypertensive and control subjects. PGA1 and PGE2 were significantly increased in renal, renovascular, labile and essential hypertension. PGFalpha was significantly increased only in patients with unilateral renal atrophy and in some patients with renovascular and essential hypertension. There was a significant positive correlation between PRA and PGA1 or B1, but not with PGE2 or Falpha. The increase of PGA and PGE represents a secondary antihypertensive, diuretic and natriuretic mechanism, the increase of PGF a direct hypertensive mechanism.
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PMID:Prostaglandins and high blood pressure. 35 39

A highly sensitive radioimmunoassay for the measurement of plasma prostaglandins A and B, expressed in equivalents of PGA1, is described. This method was used for the measurement of prostaglandins A and B (PGA/B) in 23 healthy volunteers and 25 hypertensive patients. The PGA/B concentration in peripheral venous plasma of 23 healthy normotensive subjects is 115 +/- 15 pg/ml. The repeated measurement of the same plasma samples kept frozen for 60 days at -20 degrees C shows mean 194% increase of PGA/B concentration. The major site of synthesis of PGA/B seems to be the kidney. However in two patients PGA/B concentration in arterial blood was greater than in venous blood suggesting the possibility of cardio-pulmonary synthesis. The major site of inactivation is the hepatic circulation, as PGA/B concentration in hepatal venous blood is by 30% lower than in vena caval blood. The arterial concentration is 3% lower than venous PGA/B demonstrating very low pulmonary inactivation. Therefore the prostaglandins of the A and B series may represent a "circulating hormone". The plasmatic PGA/B is significantly increased in reno-vascular and essential hypertension.
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PMID:Radioimmunoassay of prostaglandins A and B in human blood. 96 52

The renal prostaglandins PGS2 and PGE2 possess potent antihypertensive and vasodepressor activity. The mechanism of blood pressure lowering effect is through peripheral arteriolar dilation with a fall in total peripheral resistance. PGA unlike PGE escape degradation by the lung and thus could circulate as antihypertensive hormones. Since plasma PGA levels rise in humans on a low sodium intake, it has been postulated that the beneficial effects of a low sodium diet in some hypertensives may be the result of an increase in peripheral vasodilating PGA. Support that plasma PGA may be a regulator of systemic blood pressure is also derived from the fact a PGA-secreting renal tumor was associated with a fall in blood pressure and a rise in plasma PGA in a previously hypertensive woman. The removal of the tumor resulted in a return of blood pressure to elevated levels and a concomitant fall in PGA. Recently, a number of human patients with essential hypertension have been infused with PGA1 and PGA2. It was observed that there was an initial increase in renal blood flow, sodium and water excretion which was associated with no change in the elevated blood pressure. When blood pressure ultimately fell, there was a return of renal blood flow, sodium and water excretion to preinfusion levels. It would appear that PGA compounds act as 'ideal' antihypertensive agents since they favorably effect renal resistance, sodium and water homeostasis, plasma volume, total peripheral resistance, blood pressure and indirectly cardiac output through baroreceptor stimulation, all factors known to be important in etiology in human hypertension.
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PMID:Renal prostaglandins. 110 Oct 92

Substantial evidence has accumulated that the prostaglandins A (PGA) compounds, potent naturally occurring renal antihypertensive agents, may function as circulating renal vasodilators and may be responsible at least in part for the antihypertensive function of the kidney. The concept that essential hypertension is not solely the result of increased renal pressure mechanisms but may be a deficiency disorder of renal vasodepressor agents has been reinforced with isolation from the kidney of the naturally occurring peripheral vasodilator, PGA2. Along with its possible role in essential hypertension, PGA2 might function as a natriuretic "hormone." All available data indicate that the renal response to prostaglandin infusion in animals and humans with essential hypertension is characterized by an increase in cortical blood flow, glomerular filtration rate, sodium and potassium excretion, urine flow, and free-water clearance. Of all the prostaglandins investigated thus far, the most promising compounds from a cardiovascular-renal perspective are the PGA class. From their highly desirable mechanism of antihypertension and natriuretic action, the greatest immediate potential for PGA1 and PGA2 is for pharmacological use in the treatment of such disorders as hypertension and edema.
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PMID:Hypertension, natriuresis, and the renal prostaglandins. 576 18