During heat stress, blunted increases in skin sympathetic nervous system activity (SSNA) and reductions in end-organ vascular responsiveness contribute to the age-related reduction in reflex cutaneous vasodilation. In older adults, folic acid supplementation improves the cutaneous vascular conductance (CVC) response to passive heating; however, the influence of folic acid supplementation on SSNA:CVC transduction is unknown. Fourteen older adults (66±1yrs, 8M/6F) ingested folic acid (5mg·day(-1)) or placebo for 6 weeks in a randomized, double-blind, crossover design. In protocol 1, esophageal temperature (Tes) was increased by 1.0ºC (water-perfused suit) while SSNA (peroneal microneurography) and red cell flux in the innervated dermatome (laser Doppler flowmetry; dorsum of the foot) were continuously measured. In protocol 2, two intradermal microdialysis fibers were placed in the skin of the lateral calf for graded infusions of acetylcholine (ACh; 10(-10) to 10(-1)M) with and without nitric oxide synthase (NOS) blockade (20mM L-NAME). Folic acid improved reflex vasodilation (46±4% vs. 31±3 %CVCmax for placebo; P<0.001) without affecting the increase in SSNA (Δ506±104% vs. Δ415±73% for placebo; NS). Folic acid increased the slope of the SSNA:CVC relation (0.08±0.02 vs. 0.05±0.01 for placebo; P<0.05) and extended the response range. Folic acid augmented ACh-induced vasodilation (83±3% vs. 66±4 %CVCmax for placebo; P=0.002); however there was no difference between treatments at the NOS-inhibited site (53±4% vs. 52±4% CVCmax for placebo; NS). These data demonstrate that folic acid supplementation enhances reflex vasodilation by increasing the sensitivity of skin arterioles to central sympathetic nerve outflow during hyperthermia in aged human subjects.
This research output has an Altmetric Attention Score of 1. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 03 July 2020.
All research outputs
#27,764,246
of 34,411,289 outputs
Outputs from American Journal of Physiology: Regulatory, Integrative & Comparative Physiology
#3,532
of 4,369 outputs
Outputs of similar age
#271,431
of 352,671 outputs
Outputs of similar age from American Journal of Physiology: Regulatory, Integrative & Comparative Physiology
#26
of 39 outputs
Altmetric has tracked 34,411,289 research outputs across all sources so far. This one is in the 16th percentile – i.e., 16% of other outputs scored the same or lower than it.
So far Altmetric has tracked 4,369 research outputs from this source. They typically receive more attention than average, with a mean Attention Score of 9.3. This one is in the 16th percentile – i.e., 16% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 352,671 tracked outputs that were published within six weeks on either side of this one in any source. This one is in the 19th percentile – i.e., 19% of its contemporaries scored the same or lower than it.
We're also able to compare this research output to 39 others from the same source and published within six weeks on either side of this one. This one is in the 30th percentile – i.e., 30% of its contemporaries scored the same or lower than it.
