Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.11 (CD10)
 9,792 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Microvascular remodeling contributes to increased cardiovascular risk in hypertension. The dual angiotensin converting enzyme (ACE) and neutral endopeptidase (NEP) inhibitor omapatrilat improves small artery remodeling in hypertension. The aim of the present study was to compare effects of omapatrilat to the ACE inhibitor fosinopril and the AT(1) antagonist irbesartan on the coronary microvasculature in spontaneously hypertensive rats (SHR). Ten-week-old SHR were treated for 10 weeks with omapatrilat (20 or 40 mg/kg/d), irbesartan (50 mg/kg/d), or fosinopril (20 mg/kg/d). Arterioles and capillaries were identified in the myocardium by immunolabeling. After 10 weeks, systolic blood pressure (BP) was significantly reduced in treated versus untreated SHR (P <.01). Myocardial arteriolar density/mm(2) was higher (P <.05) in untreated SHR versus Wistar-Kyoto (WKY), and was reduced by omapatrilat (at both high and low doses) and by fosinopril (P <.01). Irbesartan decreased only subepicardial arteriolar density (P <.05). Myocardial capillary density/mm(2) was decreased in untreated SHR versus WKY (P <.01), associated with increase in cardiomyocyte cross-sectional area and cardiomyocyte-to-capillary ratio, and a decrease in myocyte density. Omapatrilat (at both high and low doses) resulted in increased capillary density, decreased myocyte hypertrophy and cardiomyocyte to capillary ratio, and increased myocyte density (P <.01). Fosinopril and irbesartan reduced myocyte hypertrophy of SHR, but had no effect on capillary density. Dual ACE/NEP inhibition was more effective than ACE inhibition or AT(1) antagonism in improving microvascular and cardiomyocyte remodeling in the hypertensive heart. This suggests a role for NEP inhibition added to blockade of the renin-angiotensin system that may explain the greater efficacy of omapatrilat.
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PMID:Effect of dual angiotensin converting enzyme/neutral endopeptidase inhibition, angiotensin converting enzyme inhibition, or AT1 antagonism on coronary microvasculature in spontaneously hypertensive rats. 1457 31

Neprilysin inhibitors prevent the breakdown of bradykinin and natriuretic peptides, promoting vasodilation and natriuresis. However, they also increase angiotensin II and endothelin-1. Here we studied the effects of a low and a high dose of the neprilysin inhibitor thiorphan on top of AT1 receptor blockade with irbesartan versus vehicle in TGR(mREN2)27 rats with high renin hypertension. Mean arterial blood pressure was unaffected by vehicle or thiorphan alone. Irbesartan lowered blood pressure, but after 7 days pressure started to increase again. Low- but not high-dose thiorphan prevented this rise. Only during exposure to low-dose thiorphan plus irbesartan did heart weight/body weight ratio, cardiac atrial natriuretic peptide expression, and myocyte size decrease significantly. Circulating endothelin-1 was not affected by low-dose thiorphan with or without irbesartan, but increased after treatment with high-dose thiorphan plus irbesartan. This endothelin-1 rise was accompanied by an increase in renal sodium-hydrogen exchanger 3 protein abundance, and an upregulation of constrictor vascular endothelin type B receptors. Consequently, the endothelin type B receptor antagonist BQ788 no longer enhanced endothelin-1-induced vasoconstriction (indicative of endothelin type B receptor-mediated vasodilation), but prevented it. Thus, optimal neprilysin inhibitor dosing reveals additional cardioprotective effects on top of AT1 receptor blockade in renin-dependent hypertension.
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PMID:Optimum AT1 receptor-neprilysin inhibition has superior cardioprotective effects compared with AT1 receptor blockade alone in hypertensive rats. 2583 Jul 65