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)

Vascular dementia (VaD) is the second most common type of dementia in the elderly after Alzheimer's disease (AD). Evidence is presented indicating the occurrence of cholinergic dysfunction in VaD, independent from AD. Controlled clinical trials of cholinesterase inhibitors (ChEIs) in VaD and in patients with AD plus cerebrovascular disease are reviewed. Compared with placebo, ChEI treatment improves cognition, behavior, and activities of daily living. Cholinergic deficits in patients with VaD may result from ischemia of basal forebrain cholinergic nuclei that are irrigated by penetrating arteries that are highly susceptible to arterial hypertension, or from ischemic lesions in basal ganglia or white matter that sever the extensive cholinergic cortical projections. Cholinergic stimulation produces increases in cortical cerebral blood flow that may be relevant to the therapeutic effect of ChEIs.
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PMID:Cholinergic dysfunction in vascular dementia. 1571 81

Using radiotelemetry to monitor blood pressure and core temperature, studies in our laboratory have shown that a prolonged hypertensive response is elicited in rats exposed to chlorpyrifos, an organophosphate-based insecticide. Chlorpyrifos inhibits acetylcholinesterase activity, resulting in central and peripheral stimulation of central cholinergic pathways involved in blood pressure regulation. The spontaneously hypertensive rat has been shown to be more sensitive to central cholinergic stimulation. Therefore, we hypothesized that these rats would be more susceptible and sustain a greater hypertensive response when exposed to chlorpyrifos. Heart rate, cardiac contractility, core temperature, and blood pressure were monitored by radiotelemetry in SHRs and their Wistar Kyoto (WKY) normotensive controls following exposure to chlorpyrifos (10 mg/kg or 25 mg/kg, orally). Baseline blood pressure of SHRs was approximately 35 mmHg above that of WKYs prior to dosing. SHRs exhibited a greater and more sustained elevation in diastolic, mean and systolic blood pressure following exposure to 25 mg/kg of chlorpyrifos. The rise in blood pressure lasted for approximately 56 hours in SHRs compared to approximately 32 hours in WKYs. Chlorpyrifos also led to a prolonged elevation in daytime heart rate in both strains. There was a transient elevation in cardiac contractility in both strains lasting approximately 7 hr after exposure to chlorpyrifos. The hypothermic response to chlorpyrifos was similar in magnitude and duration for both strains. Plasma cholinesterase activity measured 4 hr after exposure to 25 mg/kg chlorpyrifos was inhibited to approximately 40% of control levels in both strains. Using the SHR strain as a model to study susceptible populations, the data suggest that individuals with a genetic predisposition to hypertension may be more susceptible from exposure to organophosphate-based insecticide, as manifested by an exacerbated hypertensive response.
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PMID:The effects of chlorpyrifos on blood pressure and temperature regulation in spontaneously hypertensive rats. 1591 Apr 16

Although FDA-approved Alzheimer's disease (AD) treatment strategies (cholinesterase inhibitors and memantine) offer proven benefits, providers recognize unmet needs beyond what is currently available. Consequently there is a significant use of anecdotal yet unproven combinations for treating AD in practice. Based on the best evidence, combination drug therapy is the standard of care for treating other medical conditions such as malignancies, human immunodeficiency virus (HIV), and hypertension. We review recent combination drug therapy studies in AD. To date, the best evidence-based combination strategy is for moderate-to-severe AD, in which the addition of memantine to stable donepezil therapy was found to benefit cognition, behavior, and function. In milder stages of AD, the benefit of combination drug therapy has not been demonstrated. This review highlights the urgent need to systematically test additional rational drug combinations and the need for future trials to enroll adequate sample sizes and utilize relevant and sensitive outcome measures.
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PMID:Combination drug therapy for Alzheimer's disease: what is evidence-based, and what is not? 1594 60

We have previously demonstrated that some neurons in the anterior hypothalamic area (AHA) are tonically activated by endogenous angiotensins in rats and that activities of these AHA neurons are enhanced in spontaneously hypertensive rats (SHR). In addition, we have demonstrated that cholinergic mechanisms in the posterior hypothalamic nucleus (PHN) are involved in the activation of AHA angiotensin-II-sensitive neurons. It has been suggested that cholinergic function in the posterior hypothalamus is enhanced in SHR and that this hyperactivity plays a role in hypertension in SHR. In the present study, we examined whether the PHN cholinergic stimulation-induced activation of AHA angiotensin-II-sensitive neurons is altered in SHR. Male 15- to 16-week-old SHR and age-matched Wistar Kyoto rats (WKY) were anesthetized and artificially ventilated. Extracellular potentials were recorded from single neurons in the AHA. Microinjection of the cholinoceptor agonist carbachol, the cholinesterase inhibitor physostigmine and the excitatory amino acid glutamate into the PHN caused increases in firing rate of AHA angiotensin-II-sensitive neurons in anesthetized WKY and SHR. The increase in firing rate of AHA neurons induced by these drugs was enhanced in SHR as compared to WKY. The enhancement of the physostigmine-induced activation of AHA neurons in SHR was similar to that of the carbachol-induced activation of AHA neurons in SHR. The enhancement of the glutamate-induced activation of AHA neurons in SHR was similar to that of the carbachol-induced activation of AHA neurons in SHR. Microinjection of scopolamine, a cholinoceptor antagonist, into the PHN caused a small but significant decrease of firing rate of AHA angiotensin-II-sensitive neurons in SHR but not in WKY. These findings indicate that the PHN cholinergic stimulation-induced activation of AHA angiotensin-II-sensitive neurons is enhanced in SHR and that PHN cholinergic mechanisms are involved in tonic activation of angiotensin-II-sensitive neurons in the AHA of SHR. It appears that the enhancement of the PHN cholinergic stimulation-induced activation of AHA neurons in SHR results mainly from the enhanced neural reactivity to angiotensins in AHA neurons of SHR.
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PMID:Posterior hypothalamus cholinergic stimulation-induced activation of anterior hypothalamic area neurons is enhanced in spontaneously hypertensive rats. 1621 27

Alzheimer's disease (AD) and vascular dementia (VaD) are widely accepted as the most common forms of dementia. Cerebrovascular lesions frequently coexist with AD, creating an overlap in the clinical and pathological features of VaD and AD. This review assembles evidence for a role for cholinergic mechanisms in the pathogenesis of VaD, as has been established for AD. We first consider the anatomy and vascularization of the basal forebrain cholinergic neuronal system, emphasizing its susceptibility to the effects of arterial hypertension, sustained hypoperfusion, and ischemic cerebrovascular disease. The impact of aging and consequences of disruption of the cholinergic system in cognition and in control of cerebral blood flow are further discussed. We also summarize preclinical and clinical evidence supporting cholinergic deficits and the use of cholinesterase inhibitors in patients with VaD. We postulate that vascular pathology likely plays a common role in initiating cholinergic neuronal abnormalities in VaD and AD.
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PMID:Vascular determinants of cholinergic deficits in Alzheimer disease and vascular dementia. 1630 Aug 56

The authors used 2 national Veterans Health Administration databases to identify outpatient medications and all 30 Elixhauser comorbidities for 2579 unique patients, age 65+ years, hospitalized for syncope in fiscal year 2004. For comparison, we identified other elderly patients hospitalized with acute myocardial infarction (N = 4491), fracture (N = 2797), or pneumonia (N = 9473). The categories of medications included drugs that affect the cardiovascular, central nervous, or the muscular skeletal system. The most notable differences between syncope compared to acute myocardial infarction patients occurred in central nervous system drugs in anticonvulsants/barbiturates, antidepressants, antihistamine/antinauseants, antipsychotics, and cholinesterase inhibitors (P < .0018). Comparing syncope patients with fracture patients, the central nervous medication profile was similar, but the cardiovascular medication profile differed (P < .0018); their hypertension comorbidities also differed (60.45% vs 46.34%); (P < .0016). These findings indicate significant potential associations that warrant further study. Studies linking national outpatient medications to hospitalizations for specific conditions can foster the development of more proactive pharmacovigilance systems.
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PMID:National Veterans Health Administration hospitalizations for syncope compared to acute myocardial infarction, fracture, or pneumonia in community-dwelling elders: outpatient medication and comorbidity profiles. 1670 7

Cerebrovascular disease (CVD) is an important cause of psychiatric disability in the elderly. Much of this disability can be attributed to dementia and lesser degrees of cognitive impairment, which result from strokes and other forms of cerebrovascular pathology. While vascular dementia is common, estimates of its frequency vary due to its clinical and pathologic heterogeneity, the challenges involved in its measurement and its frequent co-occurrence with Alzheimer's disease. Nevertheless the clinical features and natural histories of vascular dementia can be described, and risk factors have been identified and include hypertension, diabetes mellitus, hyperlipidaemia, other conditions that promote atherosclerosis, and rare genetic mutations. While vascular dementia is not curable, treatments are available. For example, a few recent clinical trials suggest that cholinesterase inhibitors have some efficacy. Our knowledge of the risk factors has also provided opportunities for the primary and secondary prevention of vascular dementia, and indicates promising avenues for research.
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PMID:Cerebrovascular disease and dementia. 1708 61

Vascular dementia is a term used to describe a constellation of cognitive and functional impairment that can be viewed as a subset of the larger syndrome of vascular cognitive impairment associated with cerebrovascular brain injury. Vascular dementia is a common disorder among the elderly, although it can also occur in younger persons. Comprising 20% of all cases of dementia in the United States, vascular dementia is the second most common form of dementia after Alzheimer's disease. Patients with vascular dementia often exhibit mood and behavioral changes and may have focal neurological signs on neurological examination. Primary treatment is through primary or secondary modification of cerebrovascular risk factors such as hypertension, although symptomatic treatments with cholinesterase inhibitors have shown modest symptomatic benefit.
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PMID:Vascular dementia: emerging trends. 1722 43

Plasma levels of C-reactive protein, interleukin-6, tumor necrosis factor-alpha, and lipid peroxides are high whereas those of endothelial nitric oxide are low in insulin resistance, obesity, type 2 diabetes mellitus, hypertension, hyperlipidemias, metabolic syndrome X, and Alzheimer's disease suggesting that these diseases are characterized by low-grade systemic inflammation. Recent studies showed that the plasma and tissue activities of enzymes butyrylcholinesterase and acetylcholinesterase are elevated in patients with Alzheimer's disease, and diabetes mellitus, hypertension, insulin resistance, and hyperlipidemia. As a result of this increase in the activities of enzymes acetylcholinesterase and butyrylcholinesterase, the plasma and tissue levels of acetylcholine (ACh) will be low. The "cholinergic anti-inflammatory pathway" mediated by acetylcholine acts by inhibiting the production of tumor necrosis factor, interleukin-1, macrophage migration inhibitory factor, and high mobility group box-1 and suppresses the activation of nuclear factor-kappa B expression. ACh is a neurotransmitter and regulates the levels and activities of serotonin, dopamine and other neuropeptides and thus, modulates both immune response and neurotransmission. Hence, both acetylcholinesterase and butyrylcholinesterase by inactivating acetylcholine may enhance inflammation. This suggests that increased plasma and tissue activities of acetylcholinesterase and butyrylcholinesterase seen in various clinical conditions could serve as a marker of low-grade systemic inflammation.
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PMID:Acetylcholinesterase and butyrylcholinesterase as possible markers of low-grade systemic inflammation. 1804 45

We review the main therapeutic targets in Alzheimer's disease. Current treatments include cholinesterase inhibitors and the glutamate-modulating drug memantin. Other neurotransmitters such as serotonin, histamine and noradrenaline may also be targeted. Although useful, however, these symptomatic treatments do not prevent neuronal degeneration and death. Epidemiological studies suggest that treatments given for other reasons, such as antiinflammatory agents (including NSAIDs), cholesterol-lowering drugs, hormone replacement therapy and antioxidants, may prevent or improve Alzheimer-type dementia, but this is not always borne out in controlled clinical trials. Prevention of hypertension significantly reduces the incidence of vascular dementia and of Alzheimer-type dementia, albeit through an unknown mechanism. Alzheimer's disease is characterized by two main lesions: amyloid plaques and neurofibrillary tangles composed of aggregated A Beta peptides and hyperphosphorylated tau. Active and passive immunization against A beta has given promising results. Other exciting approaches include modulation of A beta processing by inhibiting BACE1 or gamma-secretase or upregulating alpha-secretase; A beta peptide catabolism; inhibition of beta fibrillization; and reducing tau phosphorylation or inhibiting tau aggregation. More remote possibilities include gene therapy and the use of growth factors to increase neurogenesis.
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PMID:[Alzheimer's disease: from brain lesions to new drugs]. 1881 89


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