Heat Acclimation Improves Cutaneous Vascular Function and Sweating in Trained Cyclists.
Summary of "Heat Acclimation Improves Cutaneous Vascular Function and Sweating in Trained Cyclists."
The aim of this study was to explore heat acclimation effects on cutaneous vascular responses and sweating to local acetylcholine (Ach) infusions and local heating. We also examined if heat acclimation altered maximal skin blood flow. Ach (1, 10, and 100mM) was infused in 20 highly trained cyclists via microdialysis before and after a 10-day heat acclimation (2 x 45 min exercise at 50% VO(2max) in 40°C; n = 12) program or control conditions (2 x 45 min exercise at 50% VO(2max) in 13°C; n = 8). Skin blood flow was monitored via laser-Doppler flowmetry (LDF) and cutaneous vascular conductance (CVC) was calculated as LDF/MAP. Sweat rate was measured by resistance hygrometry. Maximal forearm skin blood flow (FBF) was obtained by heating the contralateral forearm in a water spray device and measured by Doppler ultrasound. Heat acclimation increased CVC to 1, 10, and 100 mM Ach (43.5 ± 3.4 vs. 52.6 ± 2.6 %CVC(max); 67.7 ± 3.4 vs. 78.0 ± 3.0 %CVC(max); 81.0 ± 3.8 vs. 88.5 ± 1.1 %CVC(max); all P < 0.05). Maximal FBF remained unchanged after heat acclimation (290.9 ± 12.7 vs. 269.9 ± 23.6 ml min(-1)). The experimental group showed significant increases in sweating responses to 10 and 100 mM of Ach (0.21 ± 0.03 vs. 0.31 ± 0.03 mg cm(-2) min(-1); 0.45 ± 0.05 vs. 0.67 ± 0.06 mg cm(-2) min(-1); all P < 0.05) but not to 1 mM Ach (0.13 ± 0.02 vs. 0.18 ± 0.02 mg cm(-2) min(-1); p =0.147). Heat acclimation in highly trained subjects induced local adaptations within the skin microcirculation and sweat gland apparatus. Furthermore, maximal skin blood flow was not altered by heat acclimation, demonstrating that the observed changes were attributable to improvement in cutaneous vascular function and not due to structural changes that limit maximal vasodilator capacity.
1University of Oregon.
This article was published in the following journal.
Name: Journal of applied physiology (Bethesda, Md. : 1985)
- PubMed Source: http://www.ncbi.nlm.nih.gov/pubmed/20864556
- DOI: http://dx.doi.org/10.1152/japplphysiol.00725.2010
Medical and Biotech [MESH] Definitions
A clinical syndrome caused by heat stress, such as over-exertion in a hot environment or excessive exposure to sun. It is characterized by SWEATING, water (volume) depletion, salt depletion, cool clammy skin, NAUSEA, and HEADACHE.
Hsp72 Heat-shock Proteins
Stress-inducible members of the heat-shock proteins 70 family. HSP72 heat shock proteins function with other MOLECULAR CHAPERONES to mediate PROTEIN FOLDING and to stabilize pre-existent proteins against aggregation.
A dideoxynucleoside compound in which the 3'-hydroxy group on the sugar moiety has been replaced by an azido group. This modification prevents the formation of phosphodiester linkages which are needed for the completion of nucleic acid chains. The compound is a potent inhibitor of HIV replication, acting as a chain-terminator of viral DNA during reverse transcription. It improves immunologic function, partially reverses the HIV-induced neurological dysfunction, and improves certain other clinical abnormalities associated with AIDS. Its principal toxic effect is dose-dependent suppression of bone marrow, resulting in anemia and leukopenia.
Agents that are put on the SKIN to reduce SWEATING or prevent excess sweating (HYPERHIDROSIS).
An autonomic disorder characterized by excessive sweating of the forehead, upper lip, perioral region, or sternum subsequent to gustatory stimuli. The auriculotemporal syndrome features facial flushing or sweating limited to the distribution of the auriculotemporal nerve and may develop after trauma to the parotid gland, in association with PAROTID NEOPLASMS, or following their surgical removal. (From Ann Neurol 1997 Dec;42(6):973-5)
This study examined the impact of heat acclimation on improving exercise performance in a cool environment. Twelve trained cyclists performed tests of maximal aerobic power (VO(2max)), time-trial perf...
Effectiveness of short-term acclimation has generally been undertaken using untrained and moderately-trained participants. The purpose of this study was to determine the impact of short-term (5-day) h...
The purpose of the current study was to test the hypothesis that the beta-adrenergic innervation of the human eccrine sweat gland facilitates greater sweat production following heat acclimation. Eight...
Heat acclimation results in whole body-adaptations that increase heat tolerance, and might also result in changed immune responses. We hypothesized that, after heat acclimation, tumor necrosis factor...
The purpose of this study was to compare sweating function in sprinters who have trained for several years with untrained subjects and trained endurance runners. Two separate experiments were conducte...
There is growing evidence to conclude that part of the cascade leading to heatstroke is related to an inflammatory reaction triggered by the heat stress. The reduced ability to sustain hea...
This study is based on the hypothesis that terazosin, a blocker of alpha-1 receptors, will be effective in reducing excessive sweating caused by antidepressant treatment, and will have min...
An AGE-rich diet can induce after 2-6 weeks persistent increases in mediators linked to vascular dysfunction (e.g. TNFα, VCAM-1) in people with type 2 diabetes mellitus (T2DM). Benfotiami...
The purpose of this study is to determine whether lowering of fasting homocysteine concentrations improves vascular function in healthy volunteers, irrespective of the homocysteine-lowerin...
The magnesium food content in the Western world is consistently reducing. Hypomagnesemia is common in hospitalized patients, especially in the elderly with coronary artery disease (CAD) an...