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)

1. The aims of the present study were to characterize the pharmacological profile of a new endothelin (ET) receptor antagonist, TAK-044 and to consider whether it limits the extension of myocardial infarct size in rats. 2. Binding of [125I]-ET-1 to ET receptors on rabbit ventricular and cerebellar membrane fractions was inhibited by TAK-044 with IC50 values of 3.8 nM and 130 nM, respectively. 3. It inhibited ET-1, ET-2 and ET-3-induced vasoconstriction of porcine isolated coronary arteries in a competitive (ET-1, ET-2) and a non-competitive (ET-3) manner. 4. In the rat in vivo, the ET-1-induced blood pressure changes including transient hypotension followed by sustained hypertension, were inhibited by TAK-044 (0.1-10 mg kg-1, i.v.) in a dose-dependent manner. 5. Acute myocardial infarction induced by 1 h coronary occlusion followed by 24 h reperfusion in rats caused an infarct size of 60 +/- 2% (n = 12) of the area-at-risk by weight. 6. Intravenous injection of TAK-044 10 min before coronary occlusion reduced the infarct size in a dose-dependent manner: 32% and 54% reductions at 1 and 3 mg kg-1, respectively. 7. TAK-044 administered 10 min before or 1 h after reperfusion (1 mg kg-1, i.v.) showed similar inhibitory effects: 34% and 23% reductions, respectively. 8. We conclude that TAK-044 is an ETA/ETB receptor antagonist which shows strong inhibitory effects on the extension of myocardial infarct size after coronary artery occlusion-reperfusion in rats.
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PMID:Pharmacology of a non-selective ETA and ETB receptor antagonist, TAK-044 and the inhibition of myocardial infarct size in rats. 778 Jun 49

In diabetes, loss of renal arteriolar smooth-muscle cell contractility leads to intraglomerular hypertension. In glomeruli isolated from streptozotocin (STZ)-induced diabetic rats, the mesangial cells (smooth muscle-like) display loss of contractile responsiveness to angiotensin II. This study examines the mechanistic relationship between altered mesangial cell contractility and vasopressor hormone-stimulated Ca2+ signaling in high glucose. Glomeruli were isolated from normal or STZ-induced diabetic rats to observe ex vivo mesangial cell contractile function. Also, rat mesangial cells were cultured (10-20 passages) in normal (5.6 mmol/l) or high (10-25.6 mmol/l) glucose for 1-5 days. Reduction of glomerular volume and decreased planar surface area of cultured mesangial cells in response to vasoconstrictor stimulation over 60 min were measured by videomicroscopy and personal computer-based morphometry. Contraction of glomeruli isolated from STZ-administered rat in response to endothelin (ET)-1 (0.1 mumol/l) or the Ca2+ ionophore A23187 (5 mumol/l) was impaired significantly compared with that in normal glucose. In the presence of arginine vasopressin (AVP) (1.0 mumol/l) or ET-1 (0.1 mumol/l), mesangial cells demonstrated a dose-dependent loss of contractile response to increasing glucose concentrations (5.6-25.6 mmol/l) within 24 h of high-glucose exposure, which was sustained for 5 days. Mesangial cells in high glucose were consistently smaller in size compared with those in normal glucose. Mesangial cells were preloaded with myo-[2-3H]inositol and intracellular [3H] inositol phosphate release in response to AVP (1.0 mumol/l) was analyzed by Dowex chromatography. Comparing cells in normal (5.6 mmol/l) verus high (25.6 mmol/l) glucose, we observed no significant difference in stimulated inositol phosphate levels from 10 to 60 s.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Glomerular mesangial cell altered contractility in high glucose is Ca2+ independent. 778 43

1. It is generally accepted that endothelial cells secrete endothelin (ET) to the underlying media which mediates the contractile effects of ET. However, there is some evidence that animal vascular smooth muscle cells (VSMCs) also secrete ET. We cultured VSMCs from human vessels representative of a number of different vascular beds to determine whether human VSMCs endogenously secrete ET. 2. VSMCs explanted from adult arterial vessels secrete picomolar quantities of immunoreactive mature ET: coronary artery 226.6 +/- 58.8 pM/10(6) cells (n = 7), thoracic aorta 169.5 +/- 105.4 pM/10(6) cells (n = 3), left internal mammary artery 102.4 +/- 23.1 pM/10(6) cells (n = 3) and saphenous vein 69.4 +/- 19.9 pM/10(6) cells (n = 3), as well as from umbilical vein (HUVSMCs) 38.3 +/- 4.3 pM/10(6) cells (n = 3). Secretion of immunoreactive big ET-1 was also detected: coronary artery 249.1 +/- 59.4 pM/10(6) cells (n = 7), thoracic aorta 120.0 +/- 13.4 pM/10(6) cells (n = 3), left internal mammary artery 170.0 +/- 68.2 pM/10(6) cells (n = 3), saphenous vein 105.1 +/- 30.7 pM/10(6) cells (n = 3) and from umbilical vein 146.3 +/- 7.4 pM/10(6) cells (n = 3). Comparable, intracellular levels of immunoreactive big ET-1 and mature ET were also detected in cultured VSMCs. 3. Since enzyme-dispersed VSMCs are thought to be more differentiated and more closely resemble their in vivo counterparts, and these enzyme-dispersed VSMCs from human umbilical vein (HUVSMCs) also secreted the greatest levels of immunoreactive peptides, they were characterized further. Reverse transcription-polymerase chain reaction assay demonstrated that HUVSMCs express ET-1 mRNA. High performance liquid chromatography coupled to radioimmunoassay revealed that HUVSMCs secrete ET-1 and ET-3, in addition to big ET-1. However, levels of ET are not altered by 100 AM phosphoramidon,an inhibitor of metalloproteases or by 100 microM pepstatin A, an aspartyl protease inhibitor.4. In concordance, KD and Bmax values for [125I]-ET-l saturation binding are not altered in HUVSMC cultures incubated for 24 h with 100 microM phosphoramidon (431 +/- 218 PM and 31.1 +/- 12.7 fmol mg-1;mean =/- s.e.mean, n = 3) or 100 microM pepstatin A (381 +/- 169PM and 19.9 +/- 7.8 fmol mg-1, n = 3) as compared to controls (355 +/- 99 pM and 33.3 +/- 9.3 fmol mg-1; n = 3). This observation indicates the absence of an autocrine 'unmasking' effect for ET receptors.5. HUVSMCs synthesize and secrete immunoreactive ET-1, ET-3 and big ET-1, and possess intracellular levels of immunoreactive mature ET and big ET-1. There is some evidence of common cellular mechanisms between growth factors and vasoconstrictor peptides, suggesting a close relationship between contraction and proliferation. Since the development of various vascular pathologies such as atherosclerosis, hypertension and after vessel injury has been attributed to alterations in the normal growth pattern of VSMCs, the role of ET in these diseases may be of significance.
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PMID:Secretion of endothelin-1 and endothelin-3 by human cultured vascular smooth muscle cells. 788 55

An experimental model of hypertensive rat was made by abdominal aorta stenosis and hypersaline uptake. The blood pressure was significantly decreased by intracerebroventricular injection (i.c.v.) of BQ123 a potent antagonist of ET-1 receptor, in a dose-dependent manner. Negative chronotropic effect on the heart was produced by high dose of BQ123, while the depressor effect was produced by i.c.v. ET-antiserum. These results indicate that endothelin in CNS may play an important role in the pathological physiology of hypertension.
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PMID:[The depressor effect of intracerebroventricular injection of BQ123 and endothelin (ET)--antiserum on hypertensive rats produced by aorta stenosis and hypersaline uptake]. 797 32

Normal endothelin 1/2 levels and their correlation with age were evaluated and compared with endothelin 1/2 levels in hypertensive patients. Plasma endothelin 1/2 (ET) levels were measured in healthy blood donors, mostly males, of mean age 36 +/- 8 years (36 subjects), subdivided into three groups: 17-30, 31-40 and above 40 years of age (41-59 yrs). Hypertensive patients (15 subjects) were subdivided into two groups: essential and nephrogenic hypertension. The normal ET levels in the three age groups (means +/- S.D.) were: 0.58 +/- 0.19, 0.62 +/- 0.31, and 0.80 +/- 0.28 fmol/ml, respectively. The average ET level for the whole normal population was 0.66 +/- 0.28 fmol/ml. Only the differences between the mean ET levels in the first and last group were significant (P < 0.05). The difference between the mean ET levels in smokers 0.71 +/- 0.28 fmol/ml (53% of total population) and non-smokers 0.65 +/- 0.28 fmol/ml, women and men, irrespective of age, was not found to be significant. The average ET level in all patients with hypertension (0.91 +/- 0.37 fmol/ml) was significantly higher than the average ET level in blood donors of the same age group (P < 0.05). Although patients with essential hypertension had elevated ET levels compared with control, the difference between the mean ET level in these patients (0.77 +/- 0.24 fmol/ml) and in the corresponsding control group (0.62 +/- 0.31 fmol/ml) was not significant.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Plasma endothelin 1/2 levels in healthy blood donors and in hypertensive patients: clinical application. 800 15

To clarify the role of a novel vasoactive peptide endothelin in endocrine hypertension, we examined endothelin (ET)-like immunoreactivity and the ET binding sites in the tissues of two pheochromocytoma. Case 1 was a 25-year-old woman who manifested multiple endocrine neoplasia (MEN) II b with left adrenal pheochromocytoma, and case 2 was a 48-year-old woman with familial bilateral pheochromocytoma. In both cases, fairly high amount of ET-like immunoreactivity was detected in the resected tumors. By competitive binding analysis, high affinity binding sites for 125I-ET-1 were also detected in the same resected tissues. Concomitant existence of ET and its receptor suggests that ET may play an important role in these tumors in modulating the secretion of catecholamines from the tumors by an autocrine/paracrine fashion.
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PMID:[The role of endothelin in adrenal medulla: identification of endothelin and its receptor in two cases of pheochromocytoma]. 809 82

The results of this study confirm that low lead (0.01%) but not high lead (0.5%) administration results in increased blood pressure in rats treated for up to 12 months. This effect appeared to be related to an imbalance of endothelially-derived vasoconstrictor and vasodilator compounds in low lead-treated animals but not in high lead-treated animals. In low lead-treated rats, measurement of plasma endothelins 1 and 3 (ET-1 and ET-3) revealed that ET-3 concentration increased significantly after both 3 months (Experimental, 92.1 +/- 9.7 v Control, 46.7 +/- 12.0 pmol/mL; P < .001) and 12 months (Experimental, 105.0 +/- 9.3 v Control, 94.1 +/- 5.0 pmol/mL; P < .01) while ET-1 was unaffected. Plasma and urinary cGMP concentrations (as a reflection of endothelium-derived relaxing factor (EDRF)) decreased significantly at 3 months (plasma, Experimental, 1.8 +/- 0.9 v Control, 4.2 +/- 1.6 pmol/mL; P < .001) and 12 months (plasma, Experimental, 2.2 +/- 0.7 v Control, 4.2 +/- 0.9 pmol/mL; P < .001). Thus, the path to development of hypertension in low lead rats may be through an increase in the concentration of the vasoconstrictor hormone, ET-3, and a decrease in the vasodilator hormone, EDRF. High levels of lead exposure did not result in hypertension, perhaps because plasma concentrations of ET-1, ET-3 and cGMP were unaltered at 3 months, while ET-1, ET-3 and cGMP concentrations were coordinately and significantly decreased at 12 months.
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PMID:Lead-induced hypertension: possible role of endothelial factors. 811 Apr 24

Cyclosporin A (CsA) treatment is associated with hypertension and renal dysfunction. Increased circulating endothelin (ET) has been implicated in this renal dysfunction, which is secondary to renal vasoconstriction and decreases in RBF. The effects of the selective blockade of ETA receptors or the combined blockade of ETA and ETB receptors on the acute hemodynamic response to CsA in anesthetized rats were examined. Rats were pretreated with vehicle, BQ-123 (selective ETA receptor antagonist; 0.6 micron/kg per minute), or BQ-123 and PD 142893 (combined ETA/ETB receptor antagonist; 0.6 micron/kg per minute) to achieve both ETA and ETB receptor blockade. After a 10-min pretreatment, CsA (20 mg/kg over 10 min) was administered; mean arterial blood pressure, RBF, and iliac blood flow were monitored continuously. Hemodynamic responses to exogenous endothelin-1 (ET-1, 0.3 and 1 nmol/kg) with and without antagonist pretreatment were measured in separate groups to demonstrate effective receptor blockade. CsA elevated blood pressure 17 to 20% in all three groups; renal resistance maximally increased 23, 20, and 23% in vehicle, BQ-123, and BQ-123 and PD 142893 pretreated groups, respectively. In contrast, the combination of BQ-123 and PD 142893 blocked systemic pressor responses to 0.3 and 1 nmol of ET-1 approximately 50 and 37%, respectively; changes in renal resistance were blocked 81 and 89%, respectively. In conclusion, the elevation in systemic blood pressure and the renal vasoconstrictor activity of CsA do not appear to be mediated through ETA or ETB receptors.
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PMID:Effects of selective endothelin antagonists on the hemodynamic response to cyclosporin A. 816 26

To assess the possible role of ET-1 in the pathogenesis of hypertension and salt sensitivity levels of immunoreactive endothelin-1 (irET-1) were measured in plasma and urine of 17 patients with essential hypertension and in 19 normotensive control subjects. Effects of alterations in dietary sodium content on urinary irET-1 levels also were assessed. Plasma levels of irET-1 did not differ between the hypertensives and normotensive groups (1.1 +/- 0.3 and 1.3 +/- 0.1 pg/ml). Urine samples of both groups contained high concentrations of irET-1. However, the mean daily urinary excretion of irET-1 in the hypertensives was less than one-third that in controls (29 +/- 3 vs. 109 +/- 21 ng/day, respectively, P < 0.01). Changing dietary sodium content in the hypertensives had no effect on mean irET-1 excretion. However, on either low, intermediate, or high salt diet, "salt sensitive" hypertensives had lower levels of the peptide than "salt resistant" patients (23 +/- 3 vs. 36 +/- 5 ng/day, respectively, P < 0.05). The data demonstrate a marked reduction in irET-1 excretion in patients with essential hypertension, despite normal plasma levels of the peptide. Since ET-1 has diuretic and natriuretic properties, the decreased renal excretion of ET-1 may be of relevance to the pathophysiology of hypertension and salt sensitivity.
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PMID:Urinary excretion rate of endothelin-1 in patients with essential hypertension and salt sensitivity. 816 45

This study examined plasma and urinary endothelin 1 and urinary metabolites of prostacyclin and thromboxane, in women with pre-eclampsia and age and gestation matched controls. To determine if changes in endothelin 1 and urinary prostanoids in pre-eclampsia were due to hypertension per se, a comparison was made to a group of age and gestation matched pregnant uncomplicated essential hypertensive women. Measurements were taken prior to delivery, and at 6 weeks and 6 months post-partum, and were compared to a group of age matched non-pregnant controls. Plasma endothelin 1 was significantly elevated and the urinary metabolite of prostacyclin (2,3-dinor-6-keto-PGF1 alpha) was significantly suppressed in pre-eclamptic pregnancy, compared to normal pregnancy and essential hypertensive pregnancy. As the level of blood pressure was similar in the pre-eclamptic and essential hypertensive groups, these changes are not due to an increase in blood pressure per se. Urinary endothelin 1 was not different in the 3 pregnant groups prior to delivery but fell significantly after delivery. Urinary endothelin 1 was significantly lower in the essential hypertensive group at 6 weeks post-partum compared to pregnant controls with a similar trend at 6 months. Urinary 11-dehydro-TXB2 was elevated in pregnancy, but no further elevation was seen in women with pre-eclampsia. Platelet counts were lower, and circulating neutrophil counts higher in pre-eclampsia prior to delivery. A combination of increased plasma endothelin 1 and reduced tissue prostacyclin synthesis may contribute to hypertension, placental insufficiency, foetal growth retardation and renal dysfunction in pre-eclampsia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Plasma and urinary endothelin 1, prostacyclin metabolites and platelet consumption in pre-eclampsia and essential hypertensive pregnancy. 819 18


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