Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

When big endothelin-1 (big ET-1, 1-39) was incubated with the membrane fraction obtained from cultured endothelial cells (ECs) at pH 7.0 for 6 h, the immunoreactive (ir) ET in the reaction mixture was markedly increased. Phosphoramidon, a metalloproteinase inhibitor, as well as metal chelators specifically suppressed the above increase. Using reverse-phase high-performance liquid chromatography, ir-ET was confirmed to be ET-1[1-21]. In addition, we noted that the alterations in ET-1 correlated with those in the C-terminal fragment (CTF, 22-39) of big ET-1. When cultured ECs were incubated with phosphoramidon, time-dependent secretion of ET-1 and CTF from the cells was markedly suppressed. In contrast, the secretion of big ET-1 was increased by phosphoramidon. Thiorphan, a specific inhibitor of neutral endopeptidase 24.11, was without effect on the secretion of ET-related peptides. Moreover, phosphoramidon potently inhibited the hypertensive effect of big ET-1 without affecting the ET-1-induced hypertension in anesthetized rats. From these findings, it seems reasonable to consider that phosphoramidon-sensitive and membrane-bound metalloproteinase, which is not a neutral endopeptidase 24.11, is the most plausible candidate for big ET-1-converting enzyme in vivo.
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PMID:Conversion of big endothelin-1 to endothelin-1 by phosphoramidon-sensitive metalloproteinase derived from aortic endothelial cells. 172 35

It is suggested that endothelin-1 (ET-1), a potent vasoconstrictor peptide, is involved in the pathogenesis of cerebral vasospasm following subarachnoid hemorrhage (SAH). We examined the effects of intracisternal administration of big ET-1 on the cerebral arteries in the absence or presence of pretreatment with phosphoramidon, an inhibitor of ET converting enzyme, in anesthetized dogs. After intracisternal administration of big ET-1 (10 micrograms/dog), the caliber of the basilar artery on the angiogram was decreased to about 59% of the control. This was accompanied by a marked increase in immunoreactive ET in the cerebrospinal fluid. Systemic arterial pressure was markedly elevated following big ET-1 injection. All changes induced by big ET-1 were effectively prevented with phosphoramidon. These data suggest that intracisternally administered big ET-1 is converted to ET-1 and that the generated ET-1 produces cerebral vasospasm and hypertension. A phosphoramidon-sensitive metalloproteinase appears to contribute to this conversion.
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PMID:Phosphoramidon inhibits the conversion of intracisternally administered big endothelin-1 to endothelin-1. 206 64

Clear evidence has not yet come concerning the genetics of abdominal aortic aneurysms (AAA). There are circumstantial proof for a hereditary predisposition. In a retrospective study of sixty patients consecutively underwent a surgical repair for AAA, showed that one third of them knew a first-degree relative with the same disease. Environmental factors, such as smoking, ageing or hypertension, must be taken into account. A multifactorial mode of inheritance is under discussion due to both multiple genes with different expressivity and diverse environmental factors. Linkage-analysis or DNA sequencing of the different gene loci in population studies or sibbling-analysis are the tools in search for candidate genes for inheritance of AAA. Mutations in those genes encoding structural components of the aortic wall, such as collagen-type-III, fibrillin or elastin, are not taken to be the underligned genetic cause. Mutations in genes encoding enzymes for the turnover of the aortic wall components, such as alpha-1-antitrypsin or matrix-metalloproteinase-2, may play an important role.
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PMID:[Mode of genetic inheritance of abdominal aortic aneurysm: still no clear answers]. 758 55

The present study was designed to assess whether a specific endothelin A (ETA) receptor antagonist, FR139317, affects the progression of lupus nephritis and affects transcription of mRNA for extracellular matrix (ECM) components, metalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMP)-1, and accumulation of ECM proteins in the renal cortex of NZB/W F1 mice. mRNA levels for alpha 1(I), alpha 1(III), alpha 1(IV) collagen chains, laminin B1 and B2 chains, heparan sulfate proteoglycan (HSPG), MMP-1, -2, -3, and TIMP-1 increased significantly as nephritis progressed in NZB/W F1 mice. At 48 weeks of age, the levels of mRNA for alpha 1(I), alpha 1(III), alpha 1(IV) collagen chains, laminin B1 and B2 chains, HSPG, MMP-1, -2, -3, and TIMP-1 were increased by 5.6- (P < 0.001), 3.6- (P < 0.01), 6.8- (P < 0.001), 5.2- (P < 0.001), 5.0- (P < 0.001), 6.0- (P < 0.001), 7.6- (P < 0.001), 4.2- (P < 0.01), 8.2- (P < 0.001), and 15.2-fold (P < 0.001), respectively, in the renal cortex of NZB/W F1 mice compared to NZW mice. Immunofluorescence microscopy showed that the accumulation of collagens I, III, and IV, laminin, and HSPG in the renal cortex of NZB/W F1 mice increased markedly with the progression of nephritis. At 20 weeks of age, NZB/W F1 and NZW mice were divided into two groups that received either FR139317 or its vehicle (saline) intraperitoneally, daily, for 28 weeks. The development of histological lesions, proteinuria, hypertension, accumulation of collagens I, III, and IV, laminin, and HSPG in the renal cortex of NZB/W F1 mice were suppressed by FR139317 treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effect of a specific endothelin A receptor antagonist on murine lupus nephritis. 772 34

We investigated the intrarenal conversion of big endothelin-1 (ET-1) to ET-1 in the isolated perfused rat kidney. Big ET-1 caused a concentration-dependent increase in perfusion pressure, and the pressor molar potency of the peptide was 50-fold less than that of ET-1. The big ET-1 (2 x 10(-8) mol/L)-induced pressor action was accompanied by increases in immunoreactive endothelin levels in both the perfusate and renal tissues. Phosphoramidon (10(-4) mol/L), a metalloproteinase inhibitor, significantly suppressed the big ET-1-induced pressor action and the accumulation of immunoreactive endothelin in renal tissues. On the other hand, phosphoramidon slightly but significantly sustained the ET-1-induced pressor effect. The effect of kelatorphan (10(-4) mol/L), a specific inhibitor of neutral endopeptidase 24.11, on the ET-1-induced pressor effect was the same as that seen with phosphoramidon. When ET-1 was exogenously added to the perfusate, phosphoramidon or kelatorphan significantly increased the immunoreactive endothelin levels in renal tissues after perfusion, without affecting the disappearance rate of immunoreactive endothelin from the perfusate. Therefore, the phosphoramidon-sensitive ET-1-converting enzyme in the kidney seems to contribute to the functional local conversion of big ET-1 to ET-1, and neutral endopeptidase 24.11 may be responsible for the proteolytic degradation of ET-1 in the kidney. In addition, immunoreactive endothelin levels in renal tissues but not in the perfusate can account for the functional conversion of big ET-1 to ET-1 and for the local proteolytic degradation of ET-1 in the kidney.
Hypertension 1994 Aug
PMID:Phosphoramidon-sensitive conversion of big endothelin-1 and degradation of endothelin-1 in rat kidney. 803 48

Glomerular hypertension has been considered to play an important role in the development of glomerulosclerosis. Mesangial expansion, a precursor of glomerulosclerosis, may be dependent not only on synthesis of matrix but also on degradation of the deposited matrix. In the present study we investigated the effect of simulated glomerular pressure on 72 kDa metalloproteinase activity (measured as degradation of gelatin) of mesangial cells. To simulate glomerular pressure conditions we have used an in vitro mechanical stretch/relaxation system as well as an alternative system which allowed direct application of pressure on mesangial cells. Mesangial cells were grown either under control (no added pressure), stretch/relaxation, or direct mean pressure of 45-50 mm Hg (physiologic glomerular pressure) conditions. Mesangial cells grown under stretch/relaxation showed a higher (P < 0.02) level of 72 kDa metalloproteinase activity when compared with control cells (control, 6.9 +/- 0.8 vs. stretch, 9.9 +/- 0.5 ng gelatin degraded/micrograms protein). Similarly, direct stimulated glomerular pressure increased (P < 0.01) mesangial cell 72 kDa metalloproteinase activity when compared with control cells. The effect of mechanical strain on mesangial cell 72 kDa metalloproteinase activity peaked at the end of the third day (control, 4.5 +/- 1.1 vs. stretch 15.3 +/- 1.1 ng gelatin degraded/micrograms protein, P < 0.001). Both mechanical strain and direct pressure to mesangial cells modulated 72 kDa metalloproteinase activity in a dose dependent manner. Mechanical stretch equivalent to normal simulated glomerular pressure increased mesangial 72 kDa metalloproteinase activity by 88%; whereas mesangial cell 72 kDa metalloproteinase activity declined to basal levels at higher simulated glomerular pressure (equivalent to 100 mm Hg). Likewise, direct higher pressure (100 mm Hg) also lowered 72 kDa metalloproteinase activity to basal levels. These results indicate that higher glomerular pressure inhibits degradation of type IV collagen. This may cause an accumulation of extracellular matrix and may thus be contributing to the expansion of the mesangium.
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PMID:Simulated glomerular pressure modulates mesangial cell 72 kDa metalloproteinase activity. 883 43

A rapidly growing body of data support the concept of endothelin as a paracrine acting endothelial regulators. The system of endothelin peptides--their chemical structure, physiological activity and role in cardiovascular pathological processes are reviewed. Molecular specificity, isoforms, and physicochemical parameters of the endothelin-converting enzyme (ECE) characterize this novel metalloproteinase as important regulator, that catalyses final step in the biosynthesis of endothelins. The role of the general endothelial system for various cardiovascular pathological states, including congestive heart failure and myocardial infarction, arterial hypertension, atherosclerotic vascular diseases is discussed. Therapeutic approaches with some endothelin receptor antagonists and ECE inhibitors are discussed, and endothelin system therefore represents a likely target for the development for the novel pharmaceutical agents.
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PMID:[The endothelin peptide system: mechanisms of cardiovascular pathology]. 1054 78

To test the hypothesis that the activity of enzymes degrading the extracellular matrix in hypertensive patients are abnormal, and that the treatment of hypertension will normalise these abnormalities, we measured the serum levels of metalloproteinase MMP-9, and its inhibitor, tissue metalloproteinase inhibitor (TIMP-1). Thirty-two patients with untreated hypertension (BP 168/96) had significantly lower levels of both MMP-9 and TIMP-1 when compared to 24 matched normotensive controls (BP 123/80) (P<0.001). There was no significant correlation between MMP-9 and TIMP-1 levels (P>0.2). In the patients, there were no significant correlations observed between left ventricular mass, Doppler V(E)/V(A) ratio (an index of diastolic function), blood pressure, left ventricular mass index and either MMP-9 or TIMP-1 levels (all P=NS). Levels of MMP-9 and TIMP-1 were not significantly altered after 2 months of antihypertensive treatment of 29 patients despite mean blood pressure falling from 170/96 to 143/85 mmHg (P<0.001). Correspondingly, there were also no significant alterations in indices of diastolic function and left ventricular mass. Our study suggests that the proteolytic activities of MMP-9 and TIMP-l are depressed in hypertensive patients and were not significantly affected by short-term antihypertensive treatment. The relationship between collagen metabolism in hypertensive subjects, especially in those with cardiac hypertrophy, and the effects of treatment needs to be further explored in larger trials over a longer period of time.
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PMID:Matrix metalloproteinase-9 and tissue inhibitor metalloproteinase-1 levels in essential hypertension. Relationship to left ventricular mass and anti-hypertensive therapy. 1105 5

Presence or absence of three distinct bovine seminal heparin-binding proteins (21-31 kDa) recognized in sperm extracts by a monoclonal antibody, M1, is a diagnostic indicator of fertility differences among bulls producing normal semen. We recently identified a 31 kDa fertility-associated antigenin bovine seminal fluid as a unique DNase I-like protein. We now report purification and identification of a 24 kDa seminal heparin-binding protein (HBP-24) recognized by M1. N-terminal microsequence analysis of HBP-24 purified from seminal fluid yielded 20 amino acid residues that displayed 90% identity to the N-terminus of a bovine metalloproteinase inhibitor identified as tissue inhibitor of metalloproteinases-2 (TIMP-2). A single immunoreactive band migrating at 24 kDa was detected in Western blots of cauda epididymal sperm extracts following incubation with purified seminal heparin-binding proteins and subsequent washing in vitro, indicating TIMP-2 bound to sperm membranes. Expression of TIMP-2 mRNA was detected by RT-PCR in bovine bulbourethral gland, prostate, and seminal vesicles. Mobility of the 24 kDa heparin-binding protein increased under nonreducing SDS-PAGE to approximately 21 kDa, characteristic of the reported molecular mass of TIMP-2. To our knowledge, this is the first report of TIMP-2 binding to spermatozoa and of TIMP-2 mRNA expression in bovine accessory sex glands. These results corroborate previous reports regarding the site of production of heparin-binding proteins that are related to bull fertility, and suggest that TIMP-2 influences fertility of bulls, either through inhibition of metalloprotease activity in semen or via undefined activities independent of matrix metalloproteinase (MMP) inhibition.
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PMID:Identification of a heparin-binding protein in bovine seminal fluid as tissue inhibitor of metalloproteinases-2. 1117 Feb 75

Endothelin-converting enzyme 1 (ECE-1, EC 3.4.24.71) is a zinc-dependent type II mammalian membrane protein comprising the active site in the ectodomain. It exists in multiple splice variants that all catalyze the last and rate-limiting step in the activation of preproendothelin to the highly potent vasoconstrictor endothelin. There is high interest in finding small and potent inhibitors for this enzyme that could be used in numerous indications, e.g. hypertension. Since there is no structural information available for this important enzyme, we built a model of the complete ectodomain using the recently solved structure of human NEP as template. The naturally derived metalloproteinase inhibitor phosphoramidon was docked in the active site of this model and comparisons with the respective NEP complex were made.
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PMID:A three-dimensional model of endothelin-converting enzyme (ECE) based on the X-ray structure of neutral endopeptidase 24.11 (NEP). 1143 56


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