Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0917798 (cerebral ischemia)
 17,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nicardipine has high affinity for the dihydropyridine-binding site and has been shown to inhibit the influx of extracellular calcium through membrane slow channels. The calcium antagonist activity of nicardipine is greater in vascular smooth muscle than in cardiac muscle. Nicardipine has also been shown to possess greater activity in coronary than in peripheral vascular smooth muscle. This in vitro profile accounts for the decreased blood pressure and increased coronary blood flow in animal models in vivo. These pharmacologic properties are the basis for nicardipine's clinical utility in essential hypertension and acute myocardial ischemia. Nicardipine has been shown to be more vascular selective than other calcium antagonists and, therefore, possibly less inclined to produce negative inotropicity. This latter property has been confirmed in human hemodynamic studies. Nicardipine is effective in models of acute myocardial ischemia and hypertension. These results have been confirmed in antianginal and antihypertensive studies in humans. This new calcium antagonist has been shown to limit myocardial infarct size in both dogs and baboons subject to left anterior descending coronary artery ligation and to reduce the extent of ischemia-induced cerebral neuronal death in rats. Other protective effects of nicardipine have been demonstrated in paracetamol overdose in mice, chloroform-induced hepatotoxicity in rats and cerebral ischemia in gerbils and baboons. The mechanism of this cell protection of nicardipine may be related to physicochemical effects.
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PMID:Animal pharmacology of nicardipine and its clinical relevance. 244 Feb 94

Elevated serum uric acid (UA) is frequently encountered in individuals with hypertension, but whether the relationship between UA and cardiovascular events is circumstantial or causal remains to be answered. We examined the association between serum UA and left ventricular mass index (LVMI) and investigated prospectively whether the combination of UA and LVMI can predict the incidence of cardiovascular disease (CVD) in asymptomatic subjects with essential hypertension. A total of 619 subjects (mean age, 61 years; 52% female) free of prior CVD were included in this study. A significant association between UA and LVMI was also confirmed in multiple regression analysis (male: F=4.29, P<0.04; female: F=4.24, P<0.05). During follow-up (mean, 34 months), 28 subjects (14 female) developed CVD including myocardial infarction, angina pectoris, congestive heart failure, cerebral infarction, and transient cerebral ischemia. Sex-specific median values were used to separate the higher group from the lower group of UA and LVMI. Kaplan-Meier curves showed a significantly poorer survival rate in the group with higher UA and LVMI (LVMI, male: >126.9, female: >112.0 g/m2; UA, male: >374.7, female: >303.3 micromol/L; log-rank chi2=13.18; P<0.01). Multivariate Cox regression analysis showed that the combination of higher UA and LVMI was an independent predictor for CVD events (hazard ratio, 2.38; P<0.03). Our findings demonstrate that UA is independently associated with LVMI and suggest that the combination of hyperuricemia combined with left ventricular hypertrophy is an independent and powerful predictor for CVD. The association between UA and CVD events may be introduced in part because of a direct association of UA with LVMI.
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PMID:Uric acid, left ventricular mass index, and risk of cardiovascular disease in essential hypertension. 1638 May 20

In a rat model of human essential hypertension (SHR), the chronic increase in cerebral arteriolar blood pressure is accompanied by remodelling with wall hypertrophy and a fall in diameter. The latter produces an increase in cerebrovascular resistance which maintains cerebral blood flow autoregulation at high systemic blood pressure levels, but accentuates hypoperfusion at low arterial pressures such as those observed during and following cerebral ischemia. Using ACE inhibitors and AT1 blockers we have shown that the normalisation of wall thickness is pressure-dependent but that the normalisation of arteriolar diameter relates to a pressure-independent mechanism involving aldosterone. This raises the possibility of new drug targets for arteriolar remodelling involving intracellular sodium-dependent modulation of protein metabolism.
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PMID:[Renin-angiotensin-aldosterone system: an old system offering new drug targets for the cerebral circulation]. 1748 76

The paper presents a comparison of the influence of angiotensin-converting enzyme (ACE) with high (perindopril) or low (enalapril) affinity to the endothelial renin-angiotensin-aldosterone system on the dynamics of the content of humoral endothelial dysfunction markers in patients with essential hypertension (EH) complicated by ischemic cerebral stroke. The subjects of the study were patients with EH complicated by acute cerebral ischemia, who received hospital treatment with perindopril (52 patients) or enalapril (58 patients). Changes in the physical properties of the cytoplasmatic membrane and phosphatidylserine exterialization were studied in peripheral blood on lymphocyte model. In peripheral blood plasma, the dynamics of sPECAM-1 titre and antiphospholipid antibodies (APLA) were studied. All the patients had high contents of blebbing and Annexin-positive lymphocytes, as well as high sPECAM-1 and APLA titres on the 1st day of hospital treatment. These variables decreased by the 20th day of hospital stay. In patients receiving perindopril the contents of endothelial dysfunction markers under study decreased more prominantly vs. patients in the other group. The elevation of endothelial dysfunction markers is a result of its progression and oxidative stress effect. Endothelial dysfunction can be corrected, which is proved by the decrease in the level of its markers by the 20th day of hospital treatment. The most prominent therapeutic effect of perindopril is a result of its high affinity to endothelial ACE and the inhibition of bradykinin degradation.
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PMID:[The therapy of complicated forms of essential hypertension with the ACE inhibitor perindopril]. 1821 59

Calcium channel blockers (CCBs), which alter the intracellular calcium concentration by modifying calcium flux across cell membranes and affect various intracellular signaling processes, have been long and widely used to treat essential hypertension and certain types of cardiac diseases such as angina pectoris. Among five subtypes of calcium channels, only specific agents for L-type calcium channels have been used as therapeutics. Animal experiments have indicated that topical application of CCBs, especially verapamil, caused significant intraocular pressure (IOP) reductions, while ocular hypotensive effects in humans were not substantial. Although the results obtained for nifedipine and nimodipine were not always consistent, CCBs generally dilate isolated ocular vessels and increase ocular blood flow in experimental animals, normal humans, and patients with open-angle glaucoma (OAG). Several single-centered, hospital-based, prospective studies have suggested that nimodipine, brovincamine, and nilvadipine had beneficial effects on visual function not only in normal humans but also in patients with OAG, while the results of population-based and case-controlled studies were not always consistent with those obtained in hospital-based studies. In vitro studies showed that CCBs exerted neuroprotective effects on neurons undergoing apoptosis and necrosis. Although the neuroprotective effects of CCBs have been well documented in experimental cerebral ischemia models, no controlled studies have shown the clinical efficacy of CCBs in stroke or cerebral ischemia. Neuroprotective effects also were documented in retinal ganglion cells and photoreceptors in experimental animals. Some ophthalmic beta-adrenoceptor antagonists, especially betaxolol, interact with L-type calcium channels and show calcium channel-blocking activity, which may be partly responsible for the neuroprotective effects of these drugs reported in experimental animals. Based on the reported findings of CCBs and that the results of clinical studies in acute cerebral ischemia may not be directly applicable to a chronic neurodegenerative ocular disorder, such as OAG, CCBs deserve future study to investigate strategies that are additive or synergetic to ocular hypotensive therapy for OAG, especially in patients with lower IOP.
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PMID:Use of calcium channel blockers for glaucoma. 2093 4

Acute ischemia of the brainstem has been known to produce hypertension. After an initial review of central nervous system mechanisms contributing to systemic hypertension and the impact of the rostral ventrolateral medulla (RVLM) on arterial pressure, the authors propose that essential hypertension involves neurochemical changes at the level of the RVLM which are triggered by cerebral ischemia. Experimental and clinical data are presented to show that there is a link between ischemia of the brainstem and chronic hypertension. Atherosclerosis of the cerebral circulation leads to ischemia of the RVLM and other regions with autonomic function. This ischemic process results in increased availability of angiotensin II in the RVLM, which maintains the chronic hypertensive state via either direct stimulation of the RVLM or exacerbation of brainstem ischemia due to increased vasoconstriction.
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PMID:Essential hypertension as a result of neurochemical changes at the rostral ventrolateral medulla. 2405 1