Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

As an experimental model, we used 6-week-old genetically obese-hypertensive rats (SHR-fa/fa) which were obtained by transferring the fatty/fa gene of hyperlipaemic obese rats into the genome of the SHR strain: the SHR-fa/fa were bigger and more hypertensive than their SHR littermates. Studying the capacity of the hearts, kidneys, spleens, brains and lungs to synthesize PGE2, PGF2 alpha and TXA2, enabled us to show that the hearts and lungs of SHR-fa/fa synthesized more PG than those of SHR; SHR-fa/fa brains generated less icosanoids than those of SHR; the amounts of PGE2 and TXA2 produced by the kidneys are similar in SHR and in SHR-fa/fa. From the experimental data we can infer that the introduction of the fatty/fa gene into the genome of SHR does not significantly alter the capacity of the kidneys to synthesize icosanoids; the more severe hypertension in the SHR-fa/fa would result from an increase in TXA2 biosynthesis by cardiac tissue which, at the same time, synthesized more PGE2, which could be a means of defence against hypertension. Moreover this genetical manipulation inhibited the icosanoid-synthesizing capacity of the brain which thus attenuated the central nervous system activity of the animals.
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PMID:Comparative study of the biosynthesis of PGE2, PGF2 alpha and TXA2 by different organs of genetically hypertensive (SHR) and obese-hypertensive (SHR-fa/fa) rats. 346 20

An open-label study was undertaken to assess the clinical impact of multiple doses of intacervical prostaglandin E2 (0.5mg) gel administered at 6-hour intervals. 50 women in Canada with low Bishop scores requiring induction of labor were recruited. The prestudy mean Bishop score was 2.3 +or-1.1 and changed significantly with 1 (p 0.001), 2 (p 0.001), and 3 (p 0.002) doses. The mean gestational age of patients receiving 3 doses was significantly less than that of patients receiving 1 dose, (38.5 versus 40.1 weeks, p 0.005). Prostaglandin E2 gel induced labor in 55% of patients, but 14% required subsequent oxytocin (Syntocinon) augmentation. Cesarean section was performed in 6% of patients. No deleterious fetal, neonatal, or maternal effects occurred. 80% of the study group fell into the categories of postmaturity, pregnancy-induced hypertension, and intrauterine growth retardation. There appeared to be a trend toward a higher mean change in Bishop score from 6 to 12 hours in the primiparous women, but a statistically significant difference was not achieved. Surgical amniotomy was performed in 25 patients after labor was established. 47 of the patients achieved vaginal delivery. 3 Cesarean sections were performed because of cord prolapse, fetal distress, and failure to progress. Postpartum hemorrhage occurred in 3 patients.
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PMID:Clinical utility of multiple-dose administration of prostaglandin E2 gel. 346 15

Increased dietary calcium as CaCO3 had no effect in NaCl-induced hypertension in Dahl salt-sensitive (Dahl-S) rats, while the calcium supplementation as CaHPO4 did lower the blood pressure (BP). A diet rich in either monounsaturated or polyunsaturated fatty acids produced a significant lowering of blood pressure compared with the relatively saturated palm-oil diet in NaCl-induced hypertension in Dahl-S rats. The lower BP found with olive oil is probably not related to increased amounts of PGE2 and PGI2.
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PMID:Reduction of blood pressure in salt-fed Dahl salt-sensitive rats with diets rich in olive oil, safflower oil or calcium biphosphate but not with calcium carbonate. 347

Plasma renin activity (PRA) and aldosterone concentrations were measured simultaneously with urinary excretion of kallikrein and of four prostaglandins (PGE2, PGF2 alpha, 6-keto-PGF1 alpha and TXB2) in 23 patients with pregnancy-induced hypertension (PIH; 17 with permanent PIH (PH) and six with labile PIH (LH), i.e. patients whose hypertension was controlled only by home bed-rest) and in 16 normotensive pregnant women. Plasma renin activity was lower in PH than in controls or in LH. No difference between the three groups was observed for plasma aldosterone and urinary excretion of kallikrein and prostaglandins except that TXB2 was higher in LH than in PH. Thus patients with LH have a different biological profile from that of PH, since they have higher PRA and higher TXB2 excretion, an association that suggests a more pronounced ureteral compression by the gravid uterus in this group. Although no decreased synthesis of vasodilating prostaglandins was found in PH, a dysregulation of the renin-angiotensin-prostacyclin loop is suggested by a negative correlation between PRA and 6-keto-PGF1 alpha. An independent vasopressive substance which would stimulate PGI2 and suppress renin secretion is therefore postulated.
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PMID:Renin-angiotension-aldosterone system, urinary prostaglandins and kallikrein in pregnancy-induced hypertension: evidence for a dysregulation of the renin-angiotensin-prostacyclin loop. 347 17

Platelet aggregation was studied in patients with high and stable arterial hypertension that was mostly associated with the malignant syndrome, and the effect of PGE2 introduced into the blood flow as repeated intravenous infusions on platelet activity was assessed. The addition of low-dose inductor produced the greatest changes in platelet aggregation following platelet exposure to different ADP doses in the patients, as compared to normal subjects. Stimulation with 0.1 mumol ADP produced a 7-fold increase in platelet aggregation in hypertensive patients, as compared to the controls. Repeated administration of 1.2-1.5 mg PGE2 normalizes cell sensitivity to ADP. Mean arterial BP dropped by 15-45 mm Hg during the infusions and remained low for several days afterwards.
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PMID:[Platelet aggregation in severe and malignant forms of hypertension: effect of treatment with prostaglandin E2]. 347 7

The production rate of four prostanoids (PGE2, PGF2 alpha, 6-keto-PGF1 alpha and TXB2) in human umbilical cords from normal pregnancies (control) and cases with pregnancy-induced hypertension (PIH) were compared. The cords in the PIH-group produced significantly less 6-keto-PGF1 alpha and more TXB2 than did those in the control-group. Production rates of PGE2 and PGF2 alpha were almost equal in the two groups. After stimulation with angiotensin II the PIH-cords displayed a far smaller increase in 6-keto-PGF1 alpha production compared to the control cords. The responses in PGE2 and PGF2 alpha production were again equal in the two groups. The present results indicate that the angiotensin-prostanoid interactions are disturbed in fetal as well as in maternal vessels. Such a disturbance may explain the observed relative hypersensitivity to angiotensin II observed in gravidae prone to develop pregnancy-induced hypertension.
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PMID:Altered angiotensin-prostanoid interactions in umbilical arteries in pregnancy-induced hypertension. 347 16

The effect of a high linoleic acid diet on blood pressure, renal function, and urinary prostaglandin excretion was studied in rats with decreased renal mass. Subtotally nephrectomized (5/6 nephrectomy) male rats received either a 15% linoleic acid (high linoleic acid, HLA) diet containing 20% safflower oil or a 0.28% linoleic acid (low linoleic acid, LLA) diet containing 20% coconut oil. Sham-operated rats were also placed on either HLA or LLA diet. The subtotal nephrectomized rats developed similar degrees of hypertension during the first 3 weeks after subtotal nephrectomy. However, 4 weeks after subtotal nephrectomy, the rats on HLA diet had significantly lower blood pressure than the rats on LLA diet [HLA 152 +/- 3 (mean +/- SE) mm Hg versus LLA 171 +/- 3 mm Hg]. This difference persisted until termination of the experiment at 7 weeks after subtotal nephrectomy (HLA 159 +/- 7 mm Hg versus LLA 192 +/- 6 mm Hg). The GFR measured 7 weeks after subtotal nephrectomy was significantly lower in both of the subtotally nephrectomized groups. However, the HLA subtotal nephrectomized rats had significantly higher GFR than the LLA-treated rats (HLA 0.23 +/- 0.05 ml/min 100 g versus LLA 0.12 +/- 0.02 ml/min/100 g, P less than 0.05). There was no difference in the GFR or blood pressure in the sham-operated rats treated with HLA or LLA diet. PGE2 excretion was lower in the two groups of subnephrectomized rats, but there was no difference between the HLA and LLA treated rats. Urinary 6-ketoPGF1 alpha was not decreased by subtotal nephrectomy and there was no difference between the dietary groups. However, TXB2 excretion was higher in the groups with subtotal nephrectomy, but there was no difference between the two dietary groups. In conclusion, the HLA diet attenuates the rise in blood pressure after subtotal nephrectomy in the rat and preserves renal function. There was no difference in urinary excretion of PGE2, 6-keto-PFG1 alpha, or thromboxane B2 between the two dietary groups.
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PMID:Effects of dietary linoleic acid on blood pressure and renal function in subtotally nephrectomized rats. 353 27

There is evidence that neither activation of the renin-angiotensin system nor changes in sodium balance can fully explain the maintenance of blood pressure in Goldblatt hypertension. Thus, in Goldblatt two-kidney, one clip hypertension in the rat sodium balance is negative and in hypertension of a few months' duration plasma renin initially elevated has returned to normal. When hypertension is reversed by removal of the constricting clip from the renal artery, blood pressure falls within a matter of hours even when hypertension has been present for many months, suggesting that the effect of structural changes in vascular resistance vessels has been overcome. In addition, blockade of the renin-angiotensin system during renal artery declipping does not influence the pattern of the blood pressure fall. We investigated the role of the renomedullary vasodepressor system by inducing medullary necrosis with 2-bromo-ethylamine hydrobromide. This causes a moderate blood pressure increase in normal rats, and partly inhibits the fall of blood pressure in Goldblatt two-kidney, one clip hypertension when the renal clip is removed. Chemical medullectomy is associated with a slightly negative sodium balance, plasma volume contraction, a reduction in plasma renin activity and urinary PGE2, and a minimal elevation in plasma vasopressin. Blood pressure elevation appears to be attributable to inhibition of a vasodepressor system based on the renal medulla. Chemical medullectomy offers a valuable tool for investigating the role of this medullary vasodepressor system.
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PMID:Vasodepressor mechanisms in experimental hypertension: studies using chemical medullectomy. 353 84

The activity of basal 24-hour urinary kallikrein activity (UKA), prostaglandin E2 (U. PGE2) and thromboxane B2 (U. TxB2) and their relationship to natriuresis (U. Sodium), urinary aldosterone (U. Aldosterone) and plasma renin activity (in supine position: PRA1; in standing position: PRA2) were evaluated in 20 patients with early-moderate hemodynamically defined (first pass and gate blood pool radionuclide angiocardiography) essential hypertension (H) and in 13 age-matched normotensive patients (N). In basal conditions, UKA and PRA2 were significantly reduced (p less than 0.005 and p less than 0.05, respectively) in H compared with N. However, no differences between N and H were found for U. TxB2, U. PGE2, U. Aldosterone, U. Sodium, and PRA1. All parameters were also evaluated both in H and N before and after the administration of furosemide (40 mg i.v.). In H, but not in N, furosemide induced an increase of UKA (p less than 0.05), U. TxB2 (p less than 0.05) and U. Sodium (p less than 0.001). In both H and N furosemide caused a significant rise of PRA1 (p less than 0.001 in H and p less than 0.01 in N) and PRA2 (p less than 0.001 in H and p less than 0.05 in N). In H a significant correlation was found between percent increases of U. Sodium and U. Kallikrein (r = 0.54, p less than 0.01) and between percent differences of PGE2 and TxB2 (r = 0.59, p less than 0.01). It is proposed that reduction of basal UKA may be an early evidence of the first stages of hypertension, i.e., in absence of renal and cardiovascular alteration. The finding is not accompanied by significant changes in urinary excretion of arachidonic acid metabolites and aldosterone. Finally, any relation between UKA values and systemic hemodynamics is lacking.
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PMID:Acute effect of furosemide on renal kallikrein and prostaglandin systems in mild to moderate essential hypertension. 354 80

In summary, prostacyclin, PGE2, and PGD2 are vasodilators and had significantly lower renal cortical and outer medullary concentrations in the borderline hypertensive S rats compared to normotensive R rats. Conversely, thromboxane is a vasoconstrictor which had significantly higher renal cortical and outer medullary concentrations in borderline hypertensive S rats compared to normotensive R rats. Thus, in borderline hypertensive S rats, both renal cortex and outer medulla have a prostaglandin pattern which favors vasoconstriction in cortical vessels and in descending vasa recta. This could partially account for the increased renal vascular resistance and low papillary plasma flows which are integral components of Dahl hypertension. The low PGE2 in S kidneys would also enhance Na reabsorption in collecting tubules and ascending limbs, thereby encouraging Na retention and hypertension.
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PMID:Prostaglandin alterations in barely hypertensive Dahl S rats. 384 5


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