Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.23.15 (renin)
 35,795 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In rats with unilateral renal artery stenosis and an intact contralateral kidney, a malignant course of hypertension (MH) may develop, which is characterized by 1) high BP levels, 2) sodium and water loss and a polyuric-polydipsic syndrome, 3) marked activation of the renin-angiotensin system, 4) malignant nephrosclerosis in the contralateral kidney and high plasma urea concentrations, and 5) deterioration of the animals' general condition. (Some rats exhibit signs of a cerebral vascular crisis; some rats die). When such rats are offered in addition to water 0.9% NaCl, they compulsively drink the saline, BP falls for some days to levels found in the other hypertensive animals, and signs of MH nearly or completely disappear. It is concluded that high saline intake has, for a limited period, a beneficial effect on the malignant course of renal hypertension in rats. The observations made are consistent with the hypothesis that salt and water loss, which ensue subsequent to an increase of BP into a critical high range might trigger the onset of malignant hypertension.
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PMID:Effects of saline drinking on malignant course of renal hypertension in rats. 126 89

Thirty-four cases of combined abdominal aortic aneurysm (AAA) and renal artery stenosis (RAS) are reported. Hypertension was found at admission in 32 subjects, the other two being well responsive to drug therapy. Angiography and selective renal vein renin assay were always performed: renal artery stenosis was unilateral in 21 (61.7%) subjects and bilateral in 13 (38.3%). In 9 cases renal artery stenosis was not correlated to the hypertensive state. Mild chronic renal insufficiency was demonstrated preoperatively in 20 patients (58.8%). Simultaneous surgical treatment was carried out in 25 cases (73.5%). Mortality was 4% (one subject), severe renal insufficiency 8% (two subjects) and permanent renal failure 4% (one subject) All complications occurred among the group with bilateral RAS. While surgical repair of AAA is always mandatory, simultaneous surgical treatment of AAA and RAS should be carried out in carefully selected cases, due to elevated mortality rates reported in the literature, in order to cure renovascular hypertension, when it is demonstrated as related to RAS, or to preserve renal functionality, when RAS is contralateral to a functionally excluded or hypotrophic kidney or it exceeds 80% of the diameter of the artery.
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PMID:Surgical approach to combined abdominal aortic aneurysm and renal artery stenosis. 129 47

Treatment with angiotensin-converting enzyme (ACE) inhibitors can begin at any time when a left ventricular dysfunction has been diagnosed. In the absence of rare contra-indications (renal artery stenosis, connective tissue disease, severe renal failure), all patients with asymptomatic or, a fortiori, symptomatic chronic heart failure can benefit from ACE inhibitors, whatever the origin of the heart failure. Among the ACE inhibitors now available, the benefits of captopril (3 daily doses) and of enalapril (2 daily doses) on all the targets of cardiac failure treatment are now well established. The effects of lisinopril on mortality are not yet known, but the haemodynamic and symptomatic benefits of this drug are also well established (with the advantage of once daily administration). Other ACE inhibitors with less numerous and less convincing trial reports can be used or rejected depending on the physician's faith in the effects of this pharmaceutical class. With all ACE inhibitors the initial dose must be very low, to be gradually increased over several days or even weeks until the highest dose tolerated is reached. ACE inhibitors can be associated with the classical treatment of cardiac failure. A previous diuretic treatment with sodium depletion may increase the risks of first dose effect and renal intolerance due to the introduction of the ACE inhibitors. Theoretically, the combination of ACE inhibitors and spironolactone is to be avoided for fear of hyperkalaemia and renal deterioration. Yet, provided some precautions are taken this combination may improve the benefits of ACE inhibition when the renin-angiotensin-aldosterone system inhibition is not optimal. However, this has yet to be demonstrated by prospective clinical trials.
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PMID:[Management of the treatment with converting enzyme inhibitors in chronic heart failure]. 129 41

In 19 patients with unilateral renal artery stenosis and subsequent renovascular hypertension plasma renin activity (PRA), plasma concentrations of atrial natriuretic peptide (ANP), erythropoietin (Epo), H+ and HCO3-, as well as pO2 and pCO2 were assessed in renal venous blood of the 'ischaemic' and normally perfused kidney, both in arterial blood and in the inferior vena cava distally from the orifices of the renal veins. PRA and ANP were significantly elevated in venous blood of the ischaemic kidney as compared with the normally perfused kidney. In contrast to PRA and ANP, plasma concentrations of Epo were similar in blood withdrawn at all vascular sites. pO2 and pCO2, as well as blood H+ and HCO3- concentrations in venous blood of the ischaemic kidney were of the same magnitude as of the normally perfused kidney. From the results presented in this paper it follows that (i) in contrast to plasma renin activity and ANP, unilateral renal 'ischaemia' does not influence plasma concentrations of Epo in renal venous blood, and (ii) chronic haemodynamic alterations do not seem to influence Epo secretion by the kidneys.
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PMID:Plasma erythropoietin concentrations in renal venous blood of patients with unilateral renovascular hypertension. 131 93

Renal glycosuria associated with the use of angiotensin-converting enzyme inhibitors has been previously reported in two patients. A third patient was studied who developed isolated glycosuria associated with lisinopril therapy. As in the two previously described patients, this patient had a normal serum glucose level, underlying hypertension, and onset of glycosuria between 2 and 16 weeks after initiation of therapy with an angiotensin-converting enzyme inhibitor. The patient had renal artery stenosis with elevated renin levels. Age, time until resolution of glycosuria, and a rise in serum creatinine level did not have a consistent relationship with glycosuria associated with angiotensin-converting enzyme inhibitor therapy. Since glycosuria was the only defect noted, without evidence of any other urinary solutes, angiotensin-converting enzyme inhibitors may exert an effect on the glucose-specific proximal tubule transport system.
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PMID:Angiotensin-converting enzyme inhibitors and glycosuria. 131 8

The relationship between the renin-angiotensin system and erythropoietin was studied in twenty patients with renal artery stenosis and hypertension. Ten of the patients had a unilaterally activated renin-angiotensin system (group 1), while ten patients had not (group 2). Plasma erythropoietin was simultaneously measured in a brachial artery and both renal veins before and 5 and 30 min after an intravenous injection of 1.25 mg enalaprilat. The mean (+/- SD) arterial erythropoietin concentration was 27.3 +/- 16.8 mU/ml in group 1 and 14.1 +/- 11.3 mU/ml in group 2 patients (P less than 0.05). There was no significant change after enalaprilat i.v. in either group. The venous erythropoietin concentration in plasma from the stenotic kidney did not differ from that of the contralateral kidney. The higher erythropoietin concentration in group 1 patients may be explained by a systemic stimulatory effect of the renin-angiotensin system on erythropoietin production. As no side-differences were found, renal vein as well as peripheral erythropoietin measurements cannot be used as a tool in the diagnosis of the functional significance of a renal artery stenosis.
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PMID:Diagnostic use of renal vein erythropoietin measurements in patients with renal artery stenosis. 132 75

Evidence suggests an important role for the renin-angiotensin system in the pathogenesis of autosomal-dominant polycystic kidney disease (ADPKD). Therefore, we studied the presence of immunoreactive renin in renal biopsies and measured the concentrations of renin in cyst fluids. Normal kidneys and kidneys with renal artery stenosis were used for comparison. In ADPKD, immunoreactive renin was present in juxtaglomerular apparatus, associated arterioles, and in some cells within the connective tissue surrounding the cysts. Vascular immunoreactive renin was less prominent than in renal artery stenosis. Increased amounts of tubular immunoreactive renin were noted in polycystic kidneys, as compared to normal kidneys and kidneys with renal artery stenosis. Cyst fluids contained renin detected by Western analysis and enzymatic activity; concentrations were greater in gradient cysts than in nongradient cysts. Seventy-four percent of the renin in gradient cysts was active as compared to 23% in nongradient cysts and 15% in plasma. To determine whether cyst epithelial cells are capable of synthesizing renin, these cells were isolated in tissue culture. Enzymatic assay of extracts from these cells revealed the presence of renin-like enzymatic activity (1.3 +/- 0.8 ng AI/mg protein/hr). The synthesis of renin by tubulocystic epithelium was confirmed by [35S]-methionine radiolabeling of cyst-derived cells, followed by immunoprecipitation and SDS-PAGE and by detection of renin mRNA by the polymerase chain reaction. These results indicate that the tubulocystic epithelium has the potential to synthesize renin. Elevated levels of active renin in renal cysts may be linked to the pathogenesis of hypertension in ADPKD. The occurrence of renin in the lining epithelium of cyst walls raises the possibility that abnormal expression of the renin-angiotensin system may, by a paracrine or autocrine mechanism, regulate epithelial hyperplasia in growing renal cysts.
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PMID:Synthesis of renin by tubulocystic epithelium in autosomal-dominant polycystic kidney disease. 140 19

Investigations for renal artery stenosis have been greatly facilitated by advances in imaging techniques. Intravenous digital subtraction angiography is now performed in all patients with progressive, drug-resistant hypertension associated with aorto-iliac lesions or with renal impairment induced by angiotensin-converting enzyme inhibitors. Yet the finding of hypertension with renal artery stenosis is not enough to make the diagnosis of renovascular hypertension, this term being reserved to hypertension reversible by revascularization. The selection of patients who may benefit from revascularization rests on urography to explore the excretory and endocrine functions of the ischaemic kidney, as well as on scintigraphy and measurement of renin levels in renal veins before and after administration of captopril. The functional data are completed by vascular exploration which helps in evaluating the usefulness and safety of revascularization: repercussions of hypertension on target organs and extension of the vascular disease to other territories. Revascularization as first-line treatment consists of percutaneous transluminal dilatation; surgery must be reserved to difficult cases, such as arterial obliteration or failed dilatation.
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PMID:[Renovascular hypertension: diagnostic and therapeutic strategy]. 141 Aug 86

A 7-year-old female was discovered to be severely hypertensive. Urinary noradrenaline excretion and plasma noradrenaline level were elevated. Plasma renin activity was markedly elevated. She was found to have a mass in the hilus of the left kidney and left renal artery stenosis. Magnetic resonance imaging (MRI) of the mass revealed an extremely bright lesion on T2 weighted image. DMSA renal scintigraphy revealed a low uptake rate (4.7%) in the left kidney. A diagnosis of extra-adrenal pheochromocytoma associated with left sided renal artery stenosis was made. The mass and left kidney were removed. Electronmicroscopic examination of the mass revealed characteristic neurosecretory granules. There was only slight fibrosis in the wall of the removed left renal artery.
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PMID:[A case of a child with extra-adrenal pheochromocytoma associated with renovascular hypertension]. 141 54

Circadian blood pressure (BP) variation were studied in patients with renovascular hypertension (RVH) and primary aldosteronism (PA). Ambulatory BP (ABP) was monitored every 5 min for 24 hrs in a ward setting in 23 patients with PA and 17 patients with RVH (13 patients with unilateral renal arterial stenosis and 4 with bilateral stenosis). In patients with RVH, ABP was monitored before and after treatment with a converting enzyme inhibitor or percutaneous transluminal angioplasty. Plasma renin activity (PRA) was high before percutaneous transluminal angioplasty in almost all patients with RVH and low in those with PA. Ordinary circadian BP variation, i.e. nocturnal fall and diurnal rise in BP, was confirmed in the patients with unilateral or bilateral renal artery stenosis. Percutaneous transluminal angioplasty successfully normalized both BP and PRA in those with RVH. Normal circadian BP variation was observed in those with RVH before the treatment with a converting enzyme inhibitor or percutaneous transluminal angioplasty as well as during treatment with the former and after treatment with the latter. Circadian BP variation in the patients with RVH was affected by the pathogenesis of renal artery stenosis alone, i.e, fibromuscular hyperplasia and atherosclerosis; with fibromuscular hyperplasia normal circadian BP variation was observed, while with atherosclerosis, nocturnal BP fall was restricted or eliminated. Circadian BP variation in those with PA before and after excision of adrenal adenoma was essentially similar to that in normal subjects and essential hypertensive patients. From these it seems that in patients with RVH or PA, circadian BP variation is not affected by hypertension per se or by pathogenesis of hypertension.
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PMID:Circadian blood pressure variation in patients with renovascular hypertension or primary aldosteronism. 142 21


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