Resting Blood Flow in the Skin: Does it Exist, and What is the Influence of Temperature, Aging, and Diabetes?

Petrofsky, Jerrold S.

doi:10.1177/193229681200600324

Cited by 40 publications

(34 citation statements)

References 102 publications

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“…There are several methods for measuring skin blood flow, including venous occlusion plethysmography, laser Doppler, ultrasound, thermostrom, photoelectric plethysmography, impedance, and radioactive isotopes [37,38]. Venous occlusion plethysmography (VOP) measures the blood flow by measuring the change in the volume of an organ or limb, usually the forearm [39].…”

Section: Detection Methods For Skin Blood Flow Variationsmentioning

confidence: 99%

“…However, because the VOP renders 6 www.escholarship.org/uc/item/37d3q23w hand ischemia, it cannot gather blood flow data for more than 13 minutes, and it cannot be used during exercise or any other type of movement. Doppler ultrasound uses the Doppler technique to measure the speed of blood flow velocity with ultrasound and finds conduit vessel diameters to determine blood flow [37]. The ultrasound head must always be perpendicular to the artery and any movement results in a large error.…”

Section: Detection Methods For Skin Blood Flow Variationsmentioning

confidence: 99%

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Infrared thermography of human face for monitoring thermoregulation performance and estimating personal thermal comfort

Ghahramani

Castro

Becerik-Gerber

et al. 2016

Building and Environment

198

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The common practice of defining operational settings for Heating, Ventilation and Air Conditioning (HVAC) systems in buildings is to use fixed set points, which assume occupants have same and static comfort requirements. However, thermal comfort varies from person to person and also changes due to climatic variations or acclimation, making it dynamic. In addition, thermal comfort in transient conditions are different from the steady state conditions, which makes the prediction of thermal comfort more difficult. Thus, thermal comfort has to be monitored over time. In this paper, we present a novel infrared thermography based technique to monitor an individual's thermoregulation performance and thermal comfort levels by measuring the skin temperature on several points on human face, which has a high density of blood vessels and is not usually covered by clothing. Unlike other methods, our method requires no continuous user input or interaction. Our results demonstrate that the monitored facial points behave differently under the heat and cold stresses and it can be explained based on the underlying vascular territories. We define two heuristics to describe the thermoneutral zone based on the observed behaviors and estimate thermal comfort for individuals with 95% confidence level. Considerable variations are observed in the thermoregulation performance and uncomfortably cool conditions metrics between the males and females. Females' thermoregulation system responses are less sensitive to the perception of warm conditions. However, similar behaviors are observed for uncomfortably cool conditions across genders.

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Section: Detection Methods For Skin Blood Flow Variationsmentioning

confidence: 99%

Section: Detection Methods For Skin Blood Flow Variationsmentioning

confidence: 99%

Infrared thermography of human face for monitoring thermoregulation performance and estimating personal thermal comfort

Ghahramani

Castro

Becerik-Gerber

et al. 2016

Building and Environment

198

View full text Add to dashboard Cite

show abstract

“…However, it has to be noted here that, for the current assessment, a series of assumptions were made which underlie the high degree of uncertainty which accompanies this approach. For example, our efforts might be hampered by 1) lack of an appropriate physiologically based skin model, 2) possible permeability limitation of intrinsic clearance in skin explants, 3) high inherent variability of skin blood flow (Petrofsky, 2012), 4) uncertainty of the drug's unbound fraction in skin, and 5) almost complete lack of suitable in vivo skin metabolism data for model validation. Besides that, current assessment exclusively focuses on the systemic elimination effect of skin metabolism.…”

Section: Discussionmentioning

confidence: 99%

Phase II Metabolism in Human Skin: Skin Explants Show Full Coverage for Glucuronidation, Sulfation,N-Acetylation, Catechol Methylation, and Glutathione Conjugation

et al. 2014

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Although skin is the largest organ of the human body, cutaneous drug metabolism is often overlooked, and existing experimental models are insufficiently validated. This proof-of-concept study investigated phase II biotransformation of 11 test substrates in fresh full-thickness human skin explants, a model containing all skin cell types. Results show that skin explants have significant capacity for glucuronidation, sulfation, N-acetylation, catechol methylation, and glutathione conjugation. Novel skin metabolites were identified, including acyl glucuronides of indomethacin and diclofenac, glucuronides of 17b-estradiol, N-acetylprocainamide, and methoxy derivatives of 4-nitrocatechol and 2,3-dihydroxynaphthalene. Measured activities for 10 mM substrate incubations spanned a 1000-fold: from the highest 4.758 pmol·mg skin ·h -1 for 17b-estradiol 17-glucuronidation. Interindividual variability was 1.4-to 13.0-fold, the highest being 4-methylumbelliferone and diclofenac glucuronidation. Reaction rates were generally linear up to 4 hours, although 24-hour incubations enabled detection of metabolites in trace amounts. All reactions were unaffected by the inclusion of cosubstrates, and freezing of the fresh skin led to loss of glucuronidation activity. The predicted whole-skin intrinsic metabolic clearances were significantly lower compared with corresponding whole-liver intrinsic clearances, suggesting a relatively limited contribution of the skin to the body's total systemic phase II enzymemediated metabolic clearance. Nevertheless, the fresh full-thickness skin explants represent a suitable model to study cutaneous phase II metabolism not only in drug elimination but also in toxicity, as formation of acyl glucuronides and sulfate conjugates could play a role in skin adverse reactions.

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“…While the subjects with diabetes had significantly less blood flow perfusing the skin during this first minute, this is not surprising since previous studies show impairment in the ability of the skin to response to heat in people with diabetes due to endothelial cell dysfunction [10,[37][38][39][40]. The blood flow in the first minute after application of the heat in either group of subjects comparing the pre and post vitamin D administration data shows no effect of vitamin D. The initial blood flow increase with heat is mediated by CGRP and SP [29,30] was unaltered by acute administration of vitamin D. But the sustained response of blood flow to heat is mediated largely by NO [30,31].…”

Section: Discussionmentioning

confidence: 86%

The use of laser Doppler blood flow to assess the effect of acute administration of vitamin D on micro vascular endothelial function in people with diabetes

Petrofsky

Alshammari

Khowailed

et al. 2013

PTRS

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Objective:To assess the effect of vitamin D administration on the skin blood flow response to occlusion and heat. Design: Cross-sectional study. Methods: Twenty age matched subjects; 10 who had diabetes and 10 who were controls were administered 4,000 IU of vitamin D3 for 3 weeks at breakfast. The function of the endothelial cells was evaluated in 2 ways; first, the response to 4 minutes of vascular occlusion of the skin was measured with a laser Doppler flow meter. Second, the skin blood flow response to local heat at 42 degrees C for 6 minutes was examined. Results:The results of the experiments showed that the blood flow response to heat was reduced after 3 weeks administration of vitamin D in the subjects with diabetes and in the control subjects (p<0.05). The response to occlusion was not significantly different within each group before and after vitamin D administration, but the group with diabetes had a significantly lower blood flow response to occlusion than did the controls (p<0.05). Conclusions: Acute doses of vitamin D may impair nitric oxide production and reduce blood flow to tissue during stressors in people with diabetes.

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Resting Blood Flow in the Skin: Does it Exist, and What is the Influence of Temperature, Aging, and Diabetes?

Cited by 40 publications

References 102 publications

Infrared thermography of human face for monitoring thermoregulation performance and estimating personal thermal comfort

Infrared thermography of human face for monitoring thermoregulation performance and estimating personal thermal comfort

Phase II Metabolism in Human Skin: Skin Explants Show Full Coverage for Glucuronidation, Sulfation,N-Acetylation, Catechol Methylation, and Glutathione Conjugation

The use of laser Doppler blood flow to assess the effect of acute administration of vitamin D on micro vascular endothelial function in people with diabetes

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