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)

In the present study, effects of angiotensin on the adrenal steroidogenesis were studied in essential hypertension, primary aldosteronism and renovascular hypertension (RVH). Angiotensin III(A III), an analogue of angiotensin II, was administered to 17 normal volunteers (9 male and 8 female), 44 patients with essential hypertension (EH) (15 with high renin; HREH, 15 with normal renin; NREH and 14 with low renin; LREH), 8 patients with primary aldosteronism (5 with adrenal adenoma; APA and 3 with bilateral adrenocortical hyperplasia; IHA) and 5 patients with renovascular hypertension. In all the patients with hypertension and normal subjects, blood pressure (BP) and plasma concentrations of progesterone (P), corticosterone (B), aldosterone (Aldo), 17 alpha-hydroxyprogesterone(17-OHP) and cortisol(F) were measured before and after intravenous administration of A III (0.1, 0.5, 1.0, 10, 20 and 40 ng/kg/min, for 15 min, respectively). 1) BP rose from 164 +/- 19/88 +/- 8 to 180 +/- 19/112 +/- 10 mmHg [systolic BP(SBP); P less than 0.01, diastolic BP(DBP); P less than 0.01] in HREH, from 162 +/- 12/96 +/- 7 to 186 +/- 11/118 +/- 8 mmHg in NREH(SBP; P less than 0.01, DBP; P less than 0.01), 165 +/- 12/94 +/- 8 to 202 +/- 12/126 +/- 9 mmHg in LREH(SBP; P less than 0.001, P less than 0.001) and 118 +/- 8/72 +/- 7 mmHg to 136 +/- 11/88 +/- 8 mmHg in controls (SBP; P less than 0.01, DBP; P less than 0.01). The elevation in NREH and LREH was greater than that in HREH and controls. The elevations of BP both in APA and IHA were remarkably greater than that in controls and as similar as LREH(APA; 174 +/- 21/103 +/- 12 to 204 +/- 18/136 +/- 8 mmHg, IHA; 176 +/- 10/104 +/- 4 to 206 +/- 17/138 +/- 10 mmHg). The elevation in RVH was similar to that in NREH(173 +/- 9/108 +/- 8 to 194 +/- 13/132 +/- 10 mmHg). 2) Plasma P increased from 25.5 +/- 7.5 to 39.5 +/- 13.8 ng/100 ml(P less than 0.001) in HREH, from 28.0 +/- 7.7 to 45.3 +/- 12.7 ng/100 ml(P less than 0.001) in NREH, from 23.8 +/- 8.2 to 47.2 +/- 19.4 ng/100 ml(P less than 0.001) in LREH and 26.6 +/- 11.0 to 43.4 +/- 14.6 ng/100 ml in controls. The increment in HREH or NREH was similar to that in controls(P less than 0.1, respectively), whereas greater than controls in LREH(P less than 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Studies on abnormalities of adrenal steroidogenesis in essential hypertension, primary aldosteronism and renovascular hypertension: responses of plasma steroids to angiotensin III]. 341 Jan 45

The renal angiotensin angiotensin type 2 receptor has been shown to mediate natriuresis, and angiotensin III, not angiotensin II, may be the preferential angiotensin type 2 receptor activator of this response. Angiotensin III is metabolized to angiotensin IV by aminopeptidase N. The present study hypothesizes that inhibition of aminopeptidase N will augment natriuretic responses to intrarenal angiotensin III in angiotension type 1 receptor-blocked rats. Rats received systemic candesartan for 24 hours before the experiment. After a 1-hour control, cumulative renal interstitial infusion of angiotensin III at 3.5, 7, 14, and 28 nmol/kg per minute (each dose for 30 minutes) or angiotensin III combined with aminopeptidase N inhibitor PC-18 was administered into 1 kidney. The contralateral control kidney received renal interstitial infusion of vehicle. In kidneys infused with angiotensin III alone, renal sodium excretion rate increased from 0.05+/-0.01 micromol/min in stepwise fashion to 0.11+/-0.01 micromol/min at 28 nmol/kg per minute of angiotensin III (overall ANOVA F=3.68; P<0.01). In angiotensin III combined with PC-18, the renal sodium excretion rate increased from 0.05+/-0.01 to 0.32+/-0.08 mumol/min at 28 nmol/kg per minute of angiotensin III (overall ANOVA F=6.2; P<0.001). The addition of intrarenal PD-123319, an angiotensin type 2 receptor antagonist, to renal interstitial angiotensin III plus PC-18 inhibited the natriuretic response. Mean arterial blood pressure and renal sodium excretion rate from control kidneys were unchanged by angiotensin III +/- PC-18 + PD-123319. Angiotensin III plus PC-18 induced a greater natriuretic response than Ang III alone (overall ANOVA F=16.9; P=0.0001). Aminopeptidase N inhibition augmented the natriuretic response to angiotensin III, suggesting that angiotensin III is a major agonist of angiotensin type 2 receptor-induced natriuresis.
Hypertension 2007 Mar
PMID:Intrarenal aminopeptidase N inhibition augments natriuretic responses to angiotensin III in angiotensin type 1 receptor-blocked rats. 1719 Aug 72

Aminopeptidase N (APN) or CD13 is a conserved type II integral membrane zinc-dependent metalloprotease in the M1 family of ectoenzymes. APN is abundant in the kidneys and central nervous system. Identified substrates include Angiotensin III (Ang III); neuropeptides, including enkephalins and endorphins; and homones, including kallidan and somatostatin. It is developmentally expressed, a myelomonocytic marker for leukemias, and a receptor for coronovirus. There is evolving support for APN in the regulation of arterial blood pressure and the pathogenesis of hypertension. In rodent strains, intracerebraventricular (i.c.v.) infusions of APN reduces, while inhibitors of APN activity have a pressor effect on blood pressure. Dysregulation of central APN has been linked to the pathogenesis of hypertension in the spontaneously hypertensive rat. There is evidence that renal tubule APN inhibits Na flux and plays a mechanistic role in salt-adaptation. A functional polymorphism of the ANP gene has been identified in the Dahl salt-sensitive rat. Signaling by APN impacting on blood pressure is likely mediated by regulation of the metabolism of Ang III to Ang IV. Whether APN regulates arterial blood pressure in humans or is a therapeutic target for hypertension are subjects for future exploration.
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PMID:Aminopeptidase N in arterial hypertension. 1800 60

The pathophysiology of heart failure (HF) and hypertension are thought to involve brain renin-angiotensin system (RAS) hyperactivity. Angiotensin III, a key effector peptide in the brain RAS, provides tonic stimulatory control over blood pressure (BP) in hypertensive rats. Aminopeptidase A (APA), the enzyme responsible for generating brain angiotensin III, constitutes a potential therapeutic target for hypertension treatment. We focus here on studies of RB150/firibastat, the first prodrug of the specific and selective APA inhibitor EC33 able to cross the blood-brain barrier. We consider its development from therapeutic target discovery to clinical trials of the prodrug. After oral administration, firibastat crosses the gastrointestinal and blood-brain barriers. On arrival in the brain, it is cleaved to generate EC33, which inhibits brain APA activity, lowering BP in various experimental models of hypertension. Firibastat was clinically and biologically well tolerated, even at high doses, in phase I trials conducted in healthy human subjects. It was then shown to decrease BP effectively in patients of various ethnic origins with hypertension in phase II trials. Brain RAS hyperactivity leads to excessive sympathetic activity, which can contribute to HF after myocardial infarction (MI). Chronic treatment with oral firibastat (4 or 8 weeks after MI) has been shown to normalize brain APA activity in mice. This effect is accompanied by a normalization of brain RAS and sympathetic activities, reducing cardiac fibrosis and hypertrophy and preventing cardiac dysfunction. Firibastat may therefore represent a novel therapeutic advance in the clinical management of patients with hypertension and potentially with HF after MI.
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PMID:Targeting Brain Aminopeptidase A: A New Strategy for the Treatment of Hypertension and Heart Failure. 3238 45