Folic acid supplementation improves microvascular function in aged humans through nitric oxide-dependent mechanisms

Older adults have reduced vascular endothelial function, evidenced by attenuated nitric oxide (NO)-dependent cutaneous vasodilation. Folic acid and its metabolite 5-methyltetrahydrofolate (5-MTHF) are reported to improve vessel function. We hypothesized that (1) local 5-MTHF administration, and (2) chronic folic acid supplementation would improve cutaneous microvascular function in aging through NO-dependent mechanisms. Eleven young (Y:22±1yrs) and 11 older (O:71±3yrs) subjects participated in 2 separate studies. In both studies, two intradermal microdialysis fibers were placed in the forearm skin for local delivery of lactated Ringer’s with and without 5mM 5-MTHF. Red cell flux was measured by laser-Doppler flowmetry (LDF). Cutaneous vascular conductance (CVC=LDF/MAP) was normalized as %CVCmax (28mM SNP, local 43°C). Study 1: After CVC plateaued during local heating, 20mM L-NAME was perfused at each site to quantify NO-dependent vasodilation. Local heating plateau (O:82±3 vs. Y:96±1%CVCmax; p=0.002) and NO-dependent vasodilation (O:26±6 vs. Y:49±5%CVCmax; p=0.03) were attenuated in older. 5-MTHF augmented overall (91±2%CVCmax; p=0.03) and NO-dependent (43±9%CVCmax; p=0.04) vasodilation in older but not young. Study 2: Subjects ingested folic acid (5mg/day) or placebo for 6wks in a randomized double-blind crossover design. A 1°C rise in oral temperature was induced using a water-perfused suit, body temperat...
Source: Clinical Science - Category: Biomedical Science Authors: Source Type: research

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This is by one of ouroutstanding 3rd year residents, Aaron Robinson, with some edits and comments by SmithEMS responded to a reported seizure in a 42 year old male. Per bystanders, he went down after some intense sporting activity, and had “shaking” type movement. He reports no personal or familial history of seizures.One of our EMS Fellows along with a Senior EM Resident were on duty that evening, and arrived on the scene with the Fire Department. When the physicians approached him, he was ashen, diaphoretic, and appeared in shock. Fire was able to obtain a BP of 60/palp and a pulse in the 40s. The physicians ...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs
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Source: Medical Science Monitor - Category: Research Tags: Med Sci Monit Source Type: research
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Source: Cardiovascular Journal of Africa - Category: Cardiology Authors: Tags: Cardiovasc J Afr Source Type: research
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Source: Journal of Critical Care - Category: Gastroenterology Source Type: research
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Source: Circulation Journal - Category: Cardiology Authors: Tags: Circ J Source Type: research
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Source: Frontiers in Physiology - Category: Physiology Source Type: research
Sympathetic nervous system dysregulation and vascular impairment in neuronal tissue beds are hallmarks of prominent cardiorespiratory diseases. However, an accurate and convenient method of assessing SNA and local vascular regulation is lacking, hindering routine clinical and research assessments. To address this, we investigated whether spectral domain optical coherence tomography (OCT), that allows investigation of retina and choroid vascular responsiveness, reflects sympathetic activity in order to develop a quick, easy and non-invasive sympathetic index. Here, we compare choroid and retina vascular perfusion density (V...
Source: Frontiers in Physiology - Category: Physiology Source Type: research
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Source: The Turkish Journal of Gastroenterology - Category: Gastroenterology Authors: Tags: Turk J Gastroenterol Source Type: research
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Source: Canadian Journal of Cardiology - Category: Cardiology Source Type: research
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Source: Journal of Thoracic Imaging - Category: Radiology Tags: Original Articles Source Type: research
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