dinoprost and Hypertension--Renal

Cyclooxygenase (COX) is a key enzyme regulating the production of various prostaglandins (PGs) from arachidonic acid. Angiotensin II has been reported to be an important inflammatory mediator, which increases COX-2. The aim of this study was to determine the role of various PGs and COX-2 in the regulation of atrial natriuretic peptide (ANP) secretion. PGF2alpha and PGD2 caused dose-dependent increases in ANP release and intra-atrial pressure. The potency for the stimulation of ANP secretion by PGF2alpha was higher than that by PGD2. In contrast, PGE2, PGI2, PGJ2, and thromboxane A2 did not show any significant effects. The increases in intra-atrial pressure and ANP secretion induced by PGF2alpha and PGD2 were significantly attenuated by the pretreatment with an inhibitor of PGF2alpha receptor. By the pretreatment with an inhibitor for phospholipase C (PLC), inositol 3-phosphate (IP3) receptor, protein kinase C (PKC), or myosin light chain kinase (MLCK), PGF2alpha-mediated increase in ANP secretion and positive inotropy were attenuated. Inhibitor for COX-1 or COX-2 did not cause any significant effects on atrial parameters. In hypertrophied rat atria, PGF2alpha-induced positive inotropy and ANP secretion were markedly attenuated whereas COX-2 inhibitor stimulated ANP secretion. The expression of COX-2 increased and the expression of PGF2alpha receptor mRNA decreased in hypertrophied rat atria. These results suggest that PGF2alpha increased the ANP secretion and positive inotropy through PLC-IP3-PKC-MLCK pathway, and the modulation of ANP secretion by COX-2 inhibitor and PGF2alpha may partly relate to the development of renal hypertension.

Topics: Animals; Atrial Function; Atrial Natriuretic Factor; Blood Pressure; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Cyclooxygenase Inhibitors; Dinoprost; Enzyme Inhibitors; Extracellular Fluid; Gene Expression; Heart Atria; Hypertension, Renal; In Vitro Techniques; Membrane Proteins; Perfusion; Prostaglandin D2; Prostaglandins; Rats; Rats, Sprague-Dawley; Receptors, Immunologic; Receptors, Prostaglandin; Renal Artery; Signal Transduction; Xanthones

ANG II promotes inflammation through nuclear factor-kappaB (NF-kappaB)-mediated induction of cytokines and reactive oxygen species (ROS). The aim of the present study was to examine the effect of tetradecylthioacetic acid (TTA), a modified fatty acid, on NF-kappaB, proinflammatory markers, ROS, and nitric oxide (NO) production in two-kidney, one-clip (2K1C) hypertension. The 2K1C TTA-treated group had lower blood pressure (128 +/- 3 mmHg) compared with 2K1C nontreated (178 +/- 5 mmHg, P < 0.001). The p50 and p65 subunits of NF-kappaB were higher in the clipped kidney (0.44 +/- 0.01 and 0.22 +/- 0.01, respectively) compared with controls (0.25 +/- 0.03 and 0.12 +/- 0.02, respectively, P < 0.001). In the 2K1C TTA-treated group, these values were similar to control levels. The same pattern of response was seen in the nonclipped kidney. In 2K1C hypertension, cytokines plasma were higher than in control: TNF-alpha was 13.5 +/- 2 pg/ml (P < 0.03), IL-1beta was 58.8 +/- 10 pg/ml (P = 0.003), IL-6 was 210 +/- 33 pg/ml (P < 0.001), and monocyte chemoattractant protein-1 was 429 +/- 21 pg/ml (P = 0.04). In the 2K1C TTA-treated group, these values were similar to controls, and the same pattern was seen in the clipped kidney. Clipping increased 8-iso-PGF-2alpha (P < 0.01) and decreased NO production (P < 0.01 vs. control) in the urine. TTA treatment normalized these values. NO production was also lower in clipped and nonclipped kidney (P < 0.001). After TTA treatment, these values were similar to controls. The results indicate that TTA has a potent anti-inflammatory effect in 2K1C by inhibition of p50/p65 NF-kappaB subunit activation, reduction of cytokines production and ROS, and enhanced NO production.

Topics: Animals; Body Weight; Chemokine CCL2; Dinoprost; Disease Models, Animal; Eating; Free Radical Scavengers; Hypertension, Renal; Interleukin-1beta; Interleukin-6; Kidney Cortex; Male; Nephritis; NF-kappa B p50 Subunit; Nitrates; Nitric Oxide; Nitrites; Rats; Rats, Wistar; Reactive Oxygen Species; Sodium, Dietary; Sulfides; Surgical Instruments; Transcription Factor RelA; Tumor Necrosis Factor-alpha

D/L-Nebivolol is a lypophilic beta1-adrenergic antagonist which is devoid of intrinsic sympathomimetic activity and can increase nitric oxide (NO) bioavailability with its subsequent vasodilating properties. The purpose of the present work was to assess the effect of long-term nebivolol administration on both renal damage and endothelial dysfunction induced by renal mass reduction (RMR) in rats. Atenolol, which does not increase NO bioavailability, was included in the study as a comparative beta-adrenoceptor antagonist.. Rats were subjected to both right nephrectomy and surgical removal of two-thirds of the left kidney in order to retain approximately one-sixth of the total renal mass. One week after ablation, rats were distributed randomly according to the following experimental groups: control group containing RMR rats without treatment; RMR rats treated daily with nebivolol for 6 months (drinking water, 8 mg/kg per day); and RMR rats treated daily with atenolol for 6 months (drinking water, 80 mg/kg per day). A group of sham-operated animals was also included.. Administration of either nebivolol or atenolol similarly reduced arterial pressure in comparison with RMR untreated animals; however, animals receiving nebivolol presented lower levels of collagen type I expression as well as lower glomerular and interstitial fibrosis than those receiving atenolol. Urinary excretion of oxidative stress markers were also lower in animals receiving nebivolol than in rats treated with atenolol. Furthermore, nebivolol prevented RMR-induced endothelial dysfunction more efficiently than atenolol.. Nebivolol protects against renal fibrosis, oxidative stress and endothelial dysfunction better than equivalent doses, in terms of arterial pressure reduction, of atenolol in a hypertensive model of renal damage induced by RMR.

Topics: Adrenergic beta-Antagonists; Animals; Benzopyrans; Dinoprost; Endothelium, Vascular; Ethanolamines; Fibrosis; Hypertension, Renal; Kidney; Male; Nebivolol; Oxidative Stress; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances

The present study was performed to evaluate the role of nitric oxide (NO) and its interaction with superoxide anion (O2-) in the regulation of blood pressure (BP) and renal function during the developmental phase of hypertension in Ren-2 transgenic rats (TGR). The first aim was to compare BP and renal functional responses to acute NO synthase (NOS) inhibition achieved by intravenous (i.v.) infusion of Nomega-nitro-L-arginine-methyl ester (L-NAME) in prehypertensive heterozygous TGR and in transgene-negative Hannover Sprague-Dawley (HanSD) rats. The second aim was to evaluate whether scavenging of O2- by infusion of the superoxide dismutase mimetic tempol increases NO bioavailability which therefore should augment BP and renal functional responses to L-NAME.. Rats were anesthetized, prepared for clearance experiments and BP and renal functional responses were evaluated in response to i.v. L-NAME administration (20 microg.100 g(-1).min(-1)) without or with tempol pretreatment (i.v., 300 microg.100 g(-1).min(-1)). In renal cortical tissue, nitrotyrosine protein expression was assessed by immunoblotting as marker of O2- production and urinary 8-epi-PGF(2alpha) excretion as marker of intrarenal oxidative stress was assessed by enzyme immunoassay.. BP, glomerular filtration rate (GFR), renal plasma flow (RPF) and sodium excretion were similar in TGR and HanSD. L-NAME infusion induced greater increases in BP in TGR than in HanSD (+42 +/- 4 vs. +25 +/- 3 mmHg, p < 0.05). In the absence of a significant change in GFR, L-NAME caused similar decreases in RPF (-32 +/- 6 and -25 +/- 4%, p < 0.05) in TGR and HanSD. Despite significantly higher renocortical expression of nitrotyrosine and urinary 8-epi-PGF2alpha excretion in TGR than in HanSD, pretreatment with tempol did not augment the rise in BP and the decrease in RPF induced by L-NAME.. The greater BP response to L-NAME in TGR suggests that prehypertensive TGR exhibit an enhanced NO activity in the systemic vasculature as compared with HanSD. Despite increased intrarenal oxidative stress in TGR, the dependency of the intrarenal vascular tone on NO appears to be similar in TGR and HanSD. The lack of a compensatory increase in renal NO activity may partially account for the enhanced renal vascular response to ANG II present in TGR.

Topics: Acute Disease; Animals; Animals, Genetically Modified; Antioxidants; Blood Pressure; Cyclic N-Oxides; Dinoprost; Enzyme Inhibitors; Glomerular Filtration Rate; Hypertension, Renal; Kidney; Male; Mice; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Renal Circulation; Renin; Sodium; Spin Labels; Tyrosine

We investigated the hypothesis that thromboxane A2 (TxA2)-prostaglandin H2 receptors (TP-Rs) mediate the hemodynamic responses and increase in reactive oxygen species (ROS) to ANG II (400 ng x kg(-1) x min(-1) sc for 14 days) using TP-R knockout (TP -/-) and wild-type (+/+) mice. TP -/- had normal basal mean arterial blood pressure (MAP) and glomerular filtration rate but reduced renal blood flow and increased filtration fraction (FF) and renal vascular resistance (RVR) and markers of ROS (thiobarbituric acid-reactive substances and 8-isoprostane PGF2alpha) and nitric oxide (NOx). Infusion of ANG II into TP +/+ increased ROS and thromboxane B2 (TxB2) and increased RVR and FF. ANG II infusion into TP -/- mice reduced ANG I and increased aldosterone but caused a blunted increase in MAP (TP -/- : +6 +/- 2 vs. TP +/+: +15 +/- 3 mmHg) and failed to increase FF, ROS, or TxB2 but increased NOx and paradoxically decreased RVR (-2.1 +/- 1.7 vs. +2.6 +/- 0.8 mmHg x ml(-1) x min(-1) x g(-1)). Blockade of AT1 receptor of TP -/- mice infused with ANG II reduced MAP (-8 mmHg) and aldosterone but did not change the RVR or ROS. In conclusion, during an ANG II slow pressor response, AT1 receptors activate TP-Rs that generate ROS and prostaglandins but inhibit NO. TP-Rs mediate all of the increase in RVR and FF, part of the increase in MAP, but are not implicated in the suppression of ANG I or increase in aldosterone. TP -/- mice have a basal increase in RVR and FF associated with ROS.

Topics: 6-Ketoprostaglandin F1 alpha; Aldosterone; Angiotensin I; Angiotensin II; Angiotensin II Type 1 Receptor Blockers; Animals; Body Weight; Dinoprost; Electrolytes; Epoprostenol; Female; Heart Rate; Hematocrit; Hypertension, Renal; Kidney; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitrates; Nitrites; Organ Size; Receptor, Angiotensin, Type 1; Receptors, Thromboxane A2, Prostaglandin H2; Renal Circulation; Specific Pathogen-Free Organisms; Thiobarbituric Acid Reactive Substances; Thromboxane B2; Urine; Vascular Resistance; Vasoconstrictor Agents

The patients suffering from hypertonic nephritis were examined for renal hemodynamics, the activity of the renin-angiotensin-aldosterone system (RAAS), excretion of PGE2 and PGF2 alpha, and for a number of the parameters of water-electrolyte homeostasis. In A series, the patients suffering from latent and hypertonic nephritis (n = 11 in each group) were compared. In B series, two groups of the patients (n = 13 in each group) suffering from hypertonic nephritis associated with moderate or grave arterial hypertension were compared. The patients under comparison belonging to A and B series did not differ as regards the sex, age, nephritis standing, serum creatinine or proteinuria. As compared with the patients suffering from latent nephritis (A series), the patients with hypertonic nephritis showed a lower effective renal plasma flow, a greater resistance of the renal vessels, lesser PGE2 secretion, and a higher serum sodium concentration. As compared with the patients suffering from moderate hypertension (B series), the patients with associated hypertonic nephritis and grave hypertension demonstrated a higher resistance of the renal vessels, a higher activity of plasma renin, a larger concentration of plasma aldosterone and its excretion with urine, as well as a greater volume of the circulating blood. It is assumed that the development of arterial hypertension associated with hypertonic nephritis may be caused by renal hemodynamics deterioration, by relative activation of the renin-angiotensin system, inhibition of the depressor prostaglandin system and sodium retention. The progression of hypertension may be related to further deterioration of renal hemodynamics attended by RAAS activation and hypervolemia.

Topics: Creatinine; Dinoprost; Dinoprostone; Female; Hemodynamics; Humans; Hypertension; Hypertension, Renal; Male; Nephritis; Proteinuria; Renin-Angiotensin System; Water-Electrolyte Balance

An estimation of renal secretion rates of PGE2 and PGF2 alpha, in parallel with renin-angiotensin-aldosterone system and catecholamines was performed on control subjects, essential hypertensive, and renovascular hypertensive patients. In essential hypertensive patients with normal plasma renin activity (PRA) and normal catecholamines level. We did not find any changes in the renal prostaglandin (PG) secretion rate as compared to the control subjects. Our results do not support the hypothesis that a reduction of PGE2 production is a specific feature of patients with essential hypertension. In renovascular hypertensive patients with unilateral renal artery stenosis we found: 1. High PRA in the renal plasma of the abnormal (with renal artery stenosis) kidney, and in peripheral plasma; 2. Decreased renal release of PGE2 from both kidneys, more distinct in abnormal kidney; 3. No changes of renal production of PGF2 alpha. The positive and negative correlation between renin-angiotensin system and renal PGs in physiological and pathological conditions was discussed.

Topics: Aldosterone; Dinoprost; Dinoprostone; Epinephrine; Humans; Hypertension; Hypertension, Renal; Kidney; Norepinephrine; Prostaglandins; Prostaglandins A; Prostaglandins E; Prostaglandins F; Renal Circulation; Renin-Angiotensin System; Water-Electrolyte Balance

The state of the renal prostaglandins (PG) system was assessed in 54 patients with essential hypertension, stage IB-IIA, as compared to that of patients with symptomatic arterial hypertensions. A decrease in renal PGE2 production, noted in all hypertensive patients and determined on the basis of its diurnal excretion, was particularly pronounced in essential hypertension. Diurnal PGE2 excretion decreased as hypertension progressed in patients with essential hypertension, and renal PGF2 alpha production became prevalent. Renal function is dependent on the level of PG production by the kidney. As renal concentration capacity decreases and renographic findings become less satisfactory, PGE2 excretion decreases as well. Salt loads can bring out functional insufficiency of the renal PG system in essential hypertension, as reflected in a much smaller increase in PGE2 excretion, as compared to the control values, at early stages of salt loading and a considerable increase in PGF2 alpha excretion. In essential hypertension, inadequate renal prostaglandin response to salt loading is, to a certain degree, related to changed renal PGE-9-ketoreductase activity.

Topics: Dinoprost; Dinoprostone; Humans; Hypertension; Hypertension, Renal; Hypertension, Renovascular; Kidney; Prostaglandins; Prostaglandins E; Prostaglandins F; Pyelonephritis; Sodium Chloride

Levels of PGE2, PGF2 alpha and renin activity were measured in renal venous blood of 29 patients with essential hypertension (EH), 23 patients with renovascular hypertension (RVH) and 10 patients with unilateral pyelonephritis and high arterial hypertension. The pattern of change in renal venous PG content was found to be related to the type of renal lesion: the level of PGE2 was lowered and PGF2 alpha/PGF2 ratio increased in the blood outflow from the kidneys of EH patients and from ischemized kidneys of RVH patients as compared to similar parameters in the outflow from contralateral kidneys of patients with RVH and pyelonephritis. Venous levels of both PGs were the highest in pyelonephritis-affected kidneys. Renal venous PG levels go down in all cases as the disease grows older. An acute drop in arterial pressure is accompanied with increased withdrawal of PGF2 alpha from the kidneys and enhanced renin activity in renal veins, while PGE2 drops simultaneously. PGF2 and PGE2 showing different trends of change in response to falling arterial pressure suggests increased transition of PGE2 to PGF2 alpha under the effect of enhanced PG-9-ketodehydrogenase activity. In the abdominal aorta, the scope of drop in arterial pressure correlates to the change in PGF2 alpha level, that is an evidence of PG direct involvement in the autoregulation of renal blood flow.

Topics: Dinoprost; Dinoprostone; Humans; Hypertension; Hypertension, Renal; Hypertension, Renovascular; Kidney; Prostaglandins E; Prostaglandins F; Pyelonephritis; Renal Artery; Renal Veins; Renin

The values of PGf2 alpha were studied in 20 renal patients with renal hypertension, with and without chronic renal insufficiency via a radioimmunologic method. A control group of 10 healthy volunteers wer used without data from arterial hypertension. Values (672.0 +/- 99.5 pg/ml), being, with statistically significant difference, increased as compared with the healthy volunteers (347.13 +/- 49.9 pg/ml) were found in renal patients with chronic renal insufficiency. With the advancement of CRI in patients with renal hypertension, PG concentration was also increased (505.5 +/- 77.6 pg/ml) but it was not significant as in the patients without CRI. The elevated values of PGF2+ alpha suggest their participation in the pathogenesis of renal hypertension.

Topics: Adult; Chronic Disease; Dinoprost; Female; Humans; Hypertension, Renal; Kidney Failure, Chronic; Male; Prostaglandins F; Pyelonephritis