Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An important antecedent to the development of late congestive heart failure is left ventricular dilatation and remodeling following myocardial infarction, which occurs in 30-40% of acute anterior transmural infarcts. Dilatation and remodeling commence within the first 24 hours following myocardial infarction and may be steadily progressive over months to years. Both the infarcted and uninfarcted regions of the myocardium are equally involved in the process. The remodeling process comprises left ventricular wall thinning (mainly due to cell slippage), chamber dilatation, and compensatory hypertrophy of the uninfarcted segment of the myocardium. The hypertrophy may initially be physiologic but may ultimately become a pathologic process, and thereby contribute to pump dysfunction. The possible reasons why the ventricular hypertrophy may ultimately be dysfunctional include alterations in local architecture and their sequelae alone or in concert with local changes in the beta-adrenergic, alpha-adrenergic, or renin angiotensin systems. At the present time, there are encouraging data to suggest that nitroglycerin, or the angiotensin converting enzyme inhibitor captopril, may ameliorate this process.
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PMID:Left ventricular dilatation and failure post-myocardial infarction: pathophysiology and possible pharmacologic interventions. 214 59

We wished to determine whether prolonged therapy with the Ca2+ channel blocker verapamil has beneficial structural and functional cardiac effects. Nine hypertensive outpatients [systolic blood pressure (SBP) 164 +/- 4 and diastolic BP (DBP) 103 +/- 4 mm Hg: men and women, blacks and whites, mean age 48.6 years] received 240-480 mg slow-release verapamil (Calan-SR) a day. BP, left ventricle (LV) wall thickness and mass, and mitral flow characteristics on echocardiography, and plasma catechols and renin were determined at 0, 5, 10, and 15 months. Patients were compared with 10 normotensive controls, of similar group composition (SBP 130 +/- 3 and DBP 82 +/- 1 mm Hg; age 47.2 years). In the hypertensive patients, SBP and DBP decreased significantly (p < 0.05), by 14 and 12 mm Hg, respectively, but remained well above that of controls and > 140/90 mm Hg. Diastolic LV septal thickness decreased from 15.3 +/- 0.6 to 14.5 +/- 1.1 mm (not significant), while diastolic LV posterior wall thickness (PWTd) decreased significantly (p < 0.05) from 15.7 +/- 0.6 to 14.1 +/- 0.7 mm after 8 months, but not to the value of the controls. LV diastolic and systolic and left atrial dimensions remained constant. Normalized LV mass, initially 60% greater than the controls, decreased slightly (11%) but nonsignificantly and remained above that of controls. Neither LV mass nor LV posterior wall thinning was correlated with reduction in BP. Patient peak systolic wall stress was initially significantly lower than that of controls.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Structural and functional myocardial responses to chronic treatment with the Ca2+ blocker verapamil (Calan-SR) in hypertensive patients. 750 68

A case of Ask-Upmark kidney is presented. An 18-year-old male patient referred to this facility presented with symptoms of hypertension, microscopic hematuria and proteinuria. A hormonal study revealed a high plasma renin activity level. Intravenous pyelography and abdominal computed tomography revealed thinning of the cortex with calyceal dilatation. Arteriography revealed a deep cortical groove in the middle portion of the kidney without renal arterial stenosis. Plasma renin activity of the left renal vein was significantly higher than that of the right renal vein. A left simple nephrectomy was performed under the diagnosis of Ask-Upmark kidney. Postoperatively, plasma renin activity returned to the normal range and a decrease in blood pressure was noted. Recent reports have suggested Ask-Upmark kidney to be a consequence of vesicoureteral reflux rather than a true congenital malformation. Our case indicated no evidence of vesicoureteral reflux and suggests that the lesion was congenital rather than acquired.
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PMID:[Ask-Upmark kidney: a case report]. 807 59

The renin-angiotensin system (RAS) is developmentally up-regulated and it is essential for kidney development in several species. Given the fact that the rat lung undergoes postnatal development, the mammalian lung possesses the highest angiotensin-converting enzyme (ACE) levels and ACE activity increases during the first weeks postpartum, we tested the hypothesis that ACE inhibition influences postnatal lung development. Rats were given the ACE inhibitor enalapril (10 mg kg(-1)) from 0 to 9 days of age and their lungs were examined at day 4 and 9. Lung structure was evaluated by means of light microscopy, and surface tension of bronchoalveolar lavage fluid was measured by means of a Wilhelmy balance. Neonatal ACE inhibition lowered the surface tension of bronchoalveolar lavage fluid and caused widening of respiratory airspaces and thinning of alveolar septa. Our results suggest that early postnatal ACE inhibition in rats interferes with lung development.
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PMID:Neonatal ACE inhibition in rats interferes with lung development. 1471 50

The mandatory use of pharmacotherapy in human heart failure (HF) impedes further study of natural history and remodeling mechanisms. We created a sheep model of chronic, severe, ischemic HF [left ventricular (LV) ejection fraction (LVEF) <35% stable over 4 wk] by selective coronary microembolization under general anesthesia and followed hemodynamic, energetic, neurohumoral, structural, and cellular responses over 6 mo. Thirty-eight sheep were induced into HF (58% success), with 23 sheep followed for 6 mo (21 sheep with sufficient data for analysis) after the LVEF stabilized (median of 3 embolizations). Early doubling of LV end-diastolic pressure persisted, as did increases in LV end-diastolic volume, LV wall stress, and LV wall thinning. Contractile impairment (LV end-systolic elastance, LV preload recruitable stroke work, and dobutamine-responsive contractile reserve) and diastolic dysfunction also remained stable. Cardiac mechanical energy efficiency did not recover. Plasma atrial natriuretic peptide levels remained elevated, but rises in plasma aldosterone and renin activity were transient. Collagen content increased 170%, the type I-to-III phenotype ratio doubled in the LV, but right ventricular collagen remained unaltered. Fas ligand cytokine levels correlated with expression of both caspase-3 and -2, suggesting a link in the apoptotic "death cascade." Caspase-3 activity also bore a close relationship to LV meridional wall stress calculated from echocardiographic and intraventricular pressure measurements. We concluded that the stability of chronic untreated severe ischemic HF depends on the recruitment of myocardial remodeling mechanisms that involve an interaction among hemodynamic load, contractile efficiency/energetics, neurohumoral activation, response of the extracellular matrix, wall stress, and the myocyte apoptotic pathway.
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PMID:Remodeling of the chronic severely failing ischemic sheep heart after coronary microembolization: functional, energetic, structural, and cellular responses. 1514 56

Ventricular remodeling after myocardial infarction is defined as progressive chamber dilation and wall thinning, which leads to functional compromise. Remodeling is mediated by active processes of inflammation, fibrosis, and cardiomyocyte dropout over the weeks and months after infarction, and, therefore, provides a large temporal therapeutic window. In experimental models, interruption of molecular and physiological pathways that contribute to cardiomyocyte loss, and the resulting unfavorable ventricular geometry, can abrogate remodeling and prevent or improve heart failure. Remodeling is multifactorial and involves several parallel cellular pathways, which means many potential therapeutic targets exist. Of late, much attention has been given to the development of cell-based therapies; however, the abundant, promising pharmacotherapeutic developments should not be overlooked. This Review examines developments in pharmacological treatment of ventricular remodeling in preclinical models of myocardial infarction-specifically, disruption of the renin-angiotensin-aldosterone system through direct renin inhibition and blockade of aldosterone synthesis and/or uptake, enhancement of endothelial nitric oxide synthase synthesis, G-protein receptor kinase inhibition, administration of erythropoietin, and interruption of apoptosis-and highlights the challenge of translating these successes to treatment of human disease. Therapeutic targeting of multiple organ systems involved in recovery after myocardial infarction might prove to be the best approach to improve patients' cardiac outcome.
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PMID:Novel pharmacotherapies to abrogate postinfarction ventricular remodeling. 1935 32

To characterize the temporal activation of the renin-angiotensin system after myocardial infarction (MI) in rabbits, we examined cardiac ANG II type 1 receptor (AT(1)R) expression and ANG II levels from 3 h to 35 days. The effects of losartan (12.5 mg.kg(-1).day(-1)) on functional and histomorphometric parameters when treatment was initiated early (3 h) and late (day 15) post-MI and maintained for different periods of time [short term (4 days), midterm (20 days), and long term (35 days)] were also studied. AT(1)R expression increased in the MI zone at 15 and 35 days (P < 0.05). ANG II levels increased (P < 0.05) in the non-MI zone at 24 h and in the MI zone as well as in plasma at 4 days and then progressively decreased until 35 days. The survival rate was significantly lower in untreated MI and early long-term-treated animals. Diastolic pressure-volume curves in MI at 35 and 56 days shifted to the right (P < 0.05). This shift was even more pronounced in long-term-treated groups (P < 0.05). Contractility decreased (P < 0.05 vs. sham) in the untreated and long-term-treated groups and was attenuated in the midterm-treated group. The early administration of losartan reduced RAM 11-positive macrophages from 4.15 +/- 0.05 to 3.05 +/- 0.02 cells/high-power field (HPF; P < 0.05) and CD45 RO-positive lymphocytes from 2.23 +/- 0.05 to 1.48 +/- 0.01 cells/HPF (P < 0.05) in the MI zone at 4 days. Long-term treatment reduced the scar collagen (MI: 70.50 +/- 2.35% and MI + losartan: 57.50 +/- 2.48, P < 0.05), determined the persistency of RAM 11-positive macrophages (3.02 +/- 0.13 cells/HPF) and CD45 RO-positive lymphocytes (2.77 +/- 0.58 cells/HPF, P < 0.05 vs. MI), and reduced the scar thinning ratio at 35 days (P < 0.05). Consequently, the temporal expressions of cardiac AT(1)R and ANG II post-MI in rabbits are different from those described in other species. Long-term treatment unfavorably modified post-MI remodeling, whereas midterm treatment attenuated this harmful effect. The delay in wound healing (early reduction and late persistency of inflammatory infiltrate) and adverse remodeling observed in long-term-treated animals might explain the unfavorable effect observed in rabbits.
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PMID:Effect of early versus late AT(1) receptor blockade with losartan on postmyocardial infarction ventricular remodeling in rabbits. 1942 18

Chronic heart rate reduction (HRR) therapy following myocardial infarction, using either the pure HRR agent ivabradine or the beta-blocker atenolol, has been shown to preserve maximal coronary perfusion, via reduction of perivascular collagen and a decrease in renin-angiotensin system activation. In addition ivabradine, but not atenolol, treatment attenuated the decline in ejection fraction and decreased left ventricular wall stress. In this study, we tested the hypothesis that cell survival within the infarct region was enhanced by these two pharmacological agents. Four weeks after ligating the left anterior descending coronary artery, the percentage of the LV that contained the infarct was similar in the untreated (MI) rats and those chronically treated with ivabradine (MI + IVA) or atenolol (MI + ATEN). However, the mean thickness (mm) of the ventricular wall containing the scar was significantly greater in the MI + IVA, 1.54 (P < or = 0.01) and the MI + ATEN 1.32, compared to 1.1 in the MI group, due to a 2-fold greater area of surviving cardiomyocytes (P < or = 0.01) in the treated rats compared to the untreated group. Regions of cell survival were usually in the subepicardium, with cardiomyocytes surrounding veins or venules. However, some hearts displayed surviving cells along the endocardium. These data suggest that HRR by either ivabradine or atenolol facilitates a more favorable O2 microenvironment via improved venous flow and decreased O2 demand. We conclude that chronic HRR by these agents may serve to limit infarct expansion and wall thinning and may serve to reduce the potential for ventricular rupture.
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PMID:Chronic heart rate reduction facilitates cardiomyocyte survival after myocardial infarction. 2022

The contribution of the intrarenal renin-angiotensin system to the development of hypertension is incompletely understood. Here, we used targeted homologous recombination to generate mice that express angiotensin-converting enzyme (ACE) in the kidney tubules but not in other tissues. Mice homozygous for this genetic modification (ACE 9/9 mice) had low BP levels, impaired ability to concentrate urine, and variable medullary thinning. In accord with the ACE distribution, these mice also had reduced circulating angiotensin II and high plasma renin concentration but maintained normal kidney angiotensin II levels. In response to chronic angiotensin I infusions, ACE 9/9 mice displayed increased kidney angiotensin II, enhanced rate of urinary angiotensin II excretion, and development of hypertension. These findings suggest that intrarenal ACE-derived angiotensin II formation, even in the absence of systemic ACE, increases kidney angiotensin II levels and promotes the development of hypertension.
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PMID:Intrarenal angiotensin-converting enzyme induces hypertension in response to angiotensin I infusion. 2111 16

The renin-angiotensin system (RAS) is reportedly involved in chronic diabetic complications such as diabetic nephropathy, but changes of the RAS in diabetic skin remain unknown. The aim of this study was to investigate the expression of angiotensin (Ang) II and its type 1 (AT1) and type 2 (AT2) receptors in diabetic skin tissues, and explore the relationship between the local RAS and pathological changes of diabetic skin. Our results showed that thinning of epidermis, degeneration of collagen, fracture of dermal layer, and atrophy/disappearance of subcutaneous fat were observed in diabetic skin. The expression level of AngII was increased in diabetic skin tissues compared to that in controls. mRNA and protein expression of AT1 receptor were also increased while the level of AT2 receptor decreased; the relative expression of AT1 to AT2 receptors was approximately threefold higher in diabetes than in controls. Furthermore, in the culture medium of primary cultured fibroblasts from diabetic skin, the concentration of AngII was significantly higher than that of normal control. The mRNA and protein expression of AT1 receptor was also increased in fibroblasts of diabetic skin compared to controls, while the protein expression of AT2 receptor was decreased. Taken together, our results suggest that the local RAS system is activated in diabetic skin and AngII receptor is likely to mediate the pathological changes of diabetic skin.
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PMID:Activation of skin renin-angiotensin system in diabetic rats. 2148 13


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