Myths and methodologies: Reliability of forearm cutaneous vasodilatation measured using laser‐Doppler flowmetry during whole‐body passive heating

2020 ◽  
Author(s):  
Mohamed R. Gemae ◽  
Ashley P. Akerman ◽  
Gregory W. McGarr ◽  
Robert D. Meade ◽  
Sean R. Notley ◽  
...  
Keyword(s):  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Whole Body ◽  
Passive Heating ◽  
Doppler Flowmetry ◽  
Cutaneous Vasodilatation

Reliability of Reflex Cutaneous Vasodilation on the Forearm Measured Using Laser‐Doppler Flowmetry During Whole‐body Passive Heating

2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Mohamed R. Gemae ◽  
Ashley P. Akerman ◽  
Greg W. McGarr ◽  
Madison D. Schmidt ◽  
Robert D. Meade ◽  
...  
Keyword(s):  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Whole Body ◽  
Passive Heating ◽  
Doppler Flowmetry ◽  
Cutaneous Vasodilation ◽  
Reflex Cutaneous Vasodilation

Cold-induced cutaneous vasoconstriction is mediated by Rho kinase in vivo in human skin

2007 ◽  
Vol 292 (4) ◽  
pp. H1700-H1705 ◽  
Author(s):  
Caitlin S. Thompson-Torgerson ◽  
Lacy A. Holowatz ◽  
Nicholas A. Flavahan ◽  
W. Larry Kenney
Keyword(s):  
Laser Doppler Flowmetry ◽  
Combined Treatment ◽  
Rho Kinase ◽  
Laser Doppler ◽  
Whole Body ◽  
Local Skin ◽  
Doppler Flowmetry ◽  
Thermoregulatory Model ◽  
Cutaneous Vasoconstriction

Cutaneous vasoconstriction (VC) is the initial thermoregulatory response to cold exposure and can be elicited through either whole body or localized skin cooling. However, the mechanisms governing local cold-induced VC are not well understood. We tested the hypothesis that Rho kinase participates in local cold-induced cutaneous VC. In seven men and women (20–27 yr of age), up to four ventral forearm skin sites were instrumented with intradermal microdialysis fibers for localized drug delivery during cooling. Skin blood flow was monitored at each site with laser-Doppler flowmetry while local skin temperature was decreased and maintained at 24°C for 40 min. Cutaneous vascular conductance (CVC; laser-Doppler flowmetry/mean arterial pressure) was expressed as percent change from 34°C baseline. During the first 5 min of cooling, CVC decreased at control sites (lactated Ringer solution) to −45 ± 6% ( P < 0.001), increased at adrenoceptor-antagonized sites (yohimbine + propranolol) to 15 ± 14% ( P = 0.002), and remained unchanged at both Rho kinase-inhibited (fasudil) and adrenoceptor-antagonized + Rho kinase-inhibited sites (yohimbine + propranolol + fasudil) (−9 ± 1%, P = 0.4 and −6 ± 2%, P = 0.4, respectively). During the last 5 min of cooling, CVC further decreased at all sites when compared with baseline values (control, −77 ± 4%, P < 0.001; adrenoceptor antagonized, −61 ± 3%, P < 0.001; Rho kinase inhibited, −34 ± 7%, P < 0.001; and adrenoceptor antagonized + Rho kinase inhibited sites, −35 ± 3%, P < 0.001). Rho kinase-inhibited and combined treatment sites were significantly attenuated when compared with both adrenoceptor-antagonized ( P < 0.01) and control sites ( P < 0.0001). Rho kinase mediates both early- and late-phase cold-induced VC, supporting in vitro findings and providing a putative mechanism through which both adrenergic and nonadrenergic cold-induced VC occurs in an in vivo human thermoregulatory model.

scholarly journals Reproducibility of Whole‐Body Cooling Response Using Laser Doppler Flowmetry

2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Kelsey S. Schwartz ◽  
Behnia R. Shirazi ◽  
James A. Lang
Keyword(s):  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Whole Body ◽  
Doppler Flowmetry ◽  
Body Cooling ◽  
Whole Body Cooling

Nitric oxide and receptors for VIP and PACAP in cutaneous active vasodilation during heat stress in humans

2012 ◽  
Vol 113 (10) ◽  
pp. 1512-1518 ◽  
Author(s):  
Dean L. Kellogg ◽  
Joan L. Zhao ◽  
Yubo Wu ◽  
John M. Johnson
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Heat Stress ◽  
Laser Doppler Flowmetry ◽  
Combined Treatment ◽  
Receptor Activation ◽  
Laser Doppler ◽  
Whole Body ◽  
Pac1 Receptor ◽  
Doppler Flowmetry

VPAC2 receptors sensitive to vasoactive intestinal polypeptide (VIP) and pituitary adenylyl cyclase activating polypeptide (PACAP), PAC1 receptors sensitive to PACAP, and nitric oxide (NO) generation by NO synthase (NOS) are all implicated in cutaneous active vasodilation (AVD) through incompletely defined mechanisms. We hypothesized that VPAC2/PAC1 receptor activation and NO are synergistic and interdependent in AVD and tested our hypothesis by examining the effects of VPAC2/PAC1 receptor blockade with and without NOS inhibition during heat stress. The VPAC2/PAC1 antagonist, pituitary adenylate cyclase activating peptide 6–38 (PACAP6–38) and the NOS inhibitor, NG-nitro-l-arginine methyl ester (l-NAME) were administered by intradermal microdialysis. PACAP6–38, l-NAME, a combination of PACAP6–38 and l-NAME, or Ringer's solution alone were perfused at four separate sites. Skin blood flow was monitored by laser-Doppler flowmetry at each site. Body temperature was controlled with water-perfused suits. Blood pressure was monitored by Finapres, and cutaneous vascular conductance (CVC) calculated (CVC = laser-Doppler flowmetry/mean arterial pressure). The protocol began with a 5- to 10-min baseline period without antagonist perfusion, followed by perfusion of PACAP6–38, l-NAME, or combined PACAP6–38 and l-NAME at the different sites in normothermia (45 min), followed by 3 min of whole body cooling. Whole body heating was then performed to induce heat stress and activate AVD. Finally, 58 mM sodium nitroprusside were perfused at all sites to effect maximal vasodilation for normalization of blood flow data. No significant differences in CVC (normalized to maximum) were found among Ringer's PACAP6–38, l-NAME, or combined antagonist sites during normothermia ( P > 0.05 among sites) or cold stress ( P > 0.05 among sites). CVC responses at all treated sites were attenuated during AVD ( P < 0.05 vs. Ringer's). Attenuation was greater at l-NAME and combined PACAP6–38- and l-NAME-treated sites than at PACAP6–38 sites ( P > 0.05). Because responses did not differ between l-NAME and combined treatment sites ( P > 0.05), we conclude that VPAC2/PAC1 receptors require NO in series to effect AVD.

Laser-Doppler flowmetry reveals rapid perfusion changes in adipose tissue of lean and obese females

2006 ◽  
Vol 291 (5) ◽  
pp. E1025-E1030 ◽  
Author(s):  
P. Wellhöner ◽  
D. Rolle ◽  
P. Lönnroth ◽  
L. Strindberg ◽  
M. Elam ◽  
...  
Keyword(s):  
Blood Flow ◽  
Adipose Tissue ◽  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Whole Body ◽  
Tissue Blood Flow ◽  
Flow Measurements ◽  
Doppler Flowmetry ◽  
Reflex Responses ◽  
Obese Subjects

The present study aimed to evaluate adipose tissue blood flow (ATBF) by means of laser-Doppler flowmetry (LDF) in humans. Lower body negative pressure (LBNP) and straining known to affect epidermal blood flow through the autonomic nervous system were performed in 11 lean and 11 obese female volunteers. ATBF changes were compared between both groups and also discriminated from skin blood flow (SBF) responses of the immediate vicinity. Additionally, LDF measurements were compared with flow measurements using 133xenon washout in 10 lean subjects during whole body cooling. LDF estimations of SBF and ATBF showed a positive correlation to 133Xe during cooling. SBF and ATBF were reduced to the same extent in both lean and obese subjects during LBNP. Straining induced divergent changes in SBF and ATBF: initially SBF decreased while ATBF increased, but toward the end of straining SBF increased above baseline and ATBF returned down to baseline level. Those changes were similar in both weight groups. Interestingly, only in obese subjects, both LBNP and straining were followed by ATBF augmentation, while SBF levels remained stable. In conclusion, LDF compares with 133Xe washout in monitoring ATBF during tonic perfusion changes. Its strength, however, lies in the detection of rapid flow alterations within the subcutaneous tissue, allowing the evaluation of reflex responses of the subcutaneous microcirculation. Interestingly, those rapid changes in SBF and ATBF can be both concordant and discordant. With regard to ATBF, vasoconstrictor components of the reflex responses were similar in lean and obese subjects, whereas vasodilatory responses were more pronounced in obese volunteers.

The response of skin perfusion and of rheological and immunological variables to intravenous prostanoid administration in Raynaud’s phenomenon secondary to collagenosis

VASA ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 243-249 ◽  
Author(s):  
Drinda ◽  
Neumann ◽  
Pöhlmann ◽  
Vogelsang ◽  
Stein ◽  
...  
Keyword(s):  
Laser Doppler Flowmetry ◽  
Raynaud’S Phenomenon ◽  
Raynaud's Phenomenon ◽  
Plasma Viscosity ◽  
Laser Doppler ◽  
Erythrocyte Aggregation ◽  
Control Group ◽  
Long Term Effects ◽  
Doppler Flowmetry

Background: Prostanoids are used in the treatment of Raynaud’s phenomenon and acral perfusion disorders secondary to collagenosis. In subjective terms, intravenous administration of these agents produces success in more than 50% of patients. The therapeutic outcome of clinical administration of alprostadil or iloprost may vary from individual to individual. Patients and methods: The following variables were analysed in a cross-over study in 27 patients with collagenosis and Raynaud’s phenomenon: plasma viscosity and erythrocyte aggregation (rheological variables), partial pressure of oxygen and laser Doppler flowmetry in the finger region, and lymphocyte phenotyping and interleukin (IL) determinations (immunological variables). Results: Laser Doppler flowmetry revealed significant differences between patients with secondary Raynaud’s phenomenon and a control group of 25 healthy subjects. Laser Doppler readings did not change significantly as a result of the treatments. Therapy with iloprost produced a reduction in IL-1beta, L-selectin (CD 62 L) and IL-6. Conclusion: The change in immunological variables due to iloprost may explain the long-term effects of prostaglandins in the treatment of Raynaud’s phenomenon. From our results it is not possible to infer any preference for iloprost or alprostadil.

Microcirculation disorders in patients with vibration disease and comorbidity

2020 ◽  
pp. 672-672
Author(s):  
A. N. Kuks ◽  
N. V. Slivnitsyna
Keyword(s):  
Type 2 Diabetes ◽  
Laser Doppler Flowmetry ◽  
Laser Doppler ◽  
Combined Effects ◽  
Doppler Flowmetry ◽  
Vibration Disease ◽  
History Of

The results of laser Doppler flowmetry in patients with vibration disease associated with the combined effects of local and general vibration with a history of type 2 diabetes are presented.

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