Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0920646 (renal ischemia)
 2,515 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Functional angiotensin II receptors have been documented in cardiac fibroblasts as well as an intracardiac aldosterone system that responds to short- and long-term physiological stimuli. In vitro, angiotensin II increased cardiac fibroblast-mediated collagen synthesis and mRNA levels of collagen type I, type III, pro-alpha1 (I) collagen, pro-alpha1 (III) collagen and fibronectin, and inhibited matrix metalloproteinase I activity. The angiotensin II-stimulated secretion and expression of collagen was completely abolished by AT1 receptor antagonism, but not affected by AT2 receptor antagonism. In vivo, chronic infusion of angiotensin II increased the collagen volume fraction in the ventricles. Angiotensin-converting enzyme (ACE) inhibition and AT1 receptor antagonism, but not AT2 receptor antagonism, reduced collagen deposition in the myocardium in spontaneously hypertensive rats and in rat myocardium following myocardial infarction. During chronic aldosterone infusion in uninephrectomized rats on a high-salt diet, a marked accumulation of interstitial and to a lesser extent perivascular collagen occurs in the heart in both ventricles. The cardiac fibrosis in this aldosterone model is prevented by spironolactone. During the continuous infusion of aldosterone in the rat, the appearance of fibrosis was delayed and started 4 weeks after the beginning of the infusion, which argues against a direct effect of aldosterone. The mechanism of aldosterone-salt-induced cardiac fibrosis possibly involves angiotensin II acting through upregulated AT1 receptors and the cardiac AT1 receptor is the target for aldosterone. An accumulation of collagen in the heart has also been found in patients with adrenal adenomas and during chronic activation of the renin-angiotensin-aldosterone system such as in surgically-induced unilateral renal ischemia, unilateral renal artery banding or renovascular hypertension. Spironolactone prevents aortic collagen accumulation in spontaneously hypertensive rats. In patients with stable chronic heart failure, spironolactone treatment in addition to diuretics and ACE inhibition reduced circulating levels of procollagen type III N-terminal aminopeptide. Also, in the Randomized Aldactone Evaluation Study, spironolactone coadministered with conventional therapy of ACE inhibitors, loop diuretics and digitalis in patients with symptomatic heart failure defined as NYHA classes III-IV, reduced total mortality by 30%.
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PMID:Role of intracardiac renin-angiotensin-aldosterone system in extracellular matrix remodeling. 1457 Dec 85

Sympathetic hyperactivity plays an important and distinct role in hypertension associated with chronic renal failure (CRF). Renal ischemia, elevated angiotensin II, and suppressed brain nitric oxide (NO) all stimulate sympathetic activity. Evidence is accumulating for a role of sympathetic hyperactivity in renal and cardiac damage in patients with CRF. Decreased NO availability and increased oxidative stress, characteristic in CRF patients, seem to sensitize target organs for damaging actions of sympathetic hyperactivity. Fortunately, sympatholytic agents can slow down progression of renal and cardiac dysfunction. Angiotensin-converting enzyme inhibitors or angiotensin II receptor antagonists suppress sympathetic activity, but complete elimination of the effect of sympathetic hyperactivity can be obtained only with specific adrenergic blockers. However, this important therapeutic option is grossly neglected, painfully illustrated by the unwillingness to treat CRF patients with beta-blockers, even if they have had a myocardial infarction. After discussion of mechanisms and effects of the sympathetic hyperactivity, a case is made for increased application of specific adrenergic blockers in patients with CRF.
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PMID:Sympathetic hyperactivity in chronic renal failure: a wake-up call. 1497 54