scholarly journals Cold‐induced cutaneous vasoconstriction in humans: Function, dysfunction and the distinctly counterproductive

2019 ◽  
Vol 104 (8) ◽  
pp. 1202-1214 ◽  
Author(s):  
Billie K. Alba ◽  
John W. Castellani ◽  
Nisha Charkoudian
Keyword(s):  
Cutaneous Vasoconstriction

Hypothermia in iron deficiency due to altered triiodothyronine metabolism

1980 ◽  
Vol 239 (5) ◽  
pp. R377-R381 ◽  
Author(s):  
E. Dillman ◽  
C. Gale ◽  
W. Green ◽  
D. G. Johnson ◽  
B. Mackler ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Iron Deficiency ◽  
Ambient Temperature ◽  
The Other ◽  
Other Hand ◽  
Iron Deficient ◽  
Catecholamine Response ◽  
Cutaneous Vasoconstriction

Iron-deficient rats become hypothermic and have an excessive catecholamine response when exposed to an ambient temperature of 4 degrees C. This is not due to changes in body insulation, since thickness is unaltered, since differences persist after removal of hair, and since cutaneous vasoconstriction is intact. On the other hand, oxygen consumption of iron-deficient animals at 4 degrees C is reduced, 39 +/- 3 ml . kg-1 . min-1 compared to 63 +/- 2 in control animals. Thyroxine (T4) values at 4 degrees C were 4.34 +/- 0.20 microgram/dl sera as compared to control values of 3.6 +/- 0.32. Triiodothyronine (T3) values of iron-deficient animals in the cold were 48 +/- 6.8 ng/dl as compared to 72 +/- 5.6 in control animals. Treatment of iron-deficient animals with iron was shown to normalize the plasma T3 response at 4 degrees C within 6 days. Thyroidectomized iron-deficient animals injected with T3 did not show hypothermia at 4 degrees C, whereas thyroidectomized iron-deficient animals injected with T4 showed hypothermia, increased catecholamines, and decreased T3 levels as compared to non-iron-deficient animals similarly treated. It is proposed that iron deficiency impairs conversion of T4 to T3 and that this is primarily responsible for the hypothermia observed.

Physical insulation of Korean diving women

1962 ◽  
Vol 17 (6) ◽  
pp. 961-966 ◽  
Author(s):  
D. W. Rennie ◽  
B. G. Covino ◽  
B. J. Howell ◽  
S. H. Song ◽  
B. S. Kang ◽  
...  
Keyword(s):  
Cold Adaptation ◽  
Water Immersion ◽  
Subcutaneous Fat ◽  
Constant Temperature Bath ◽  
Men And Women ◽  
Skin Fold Thickness ◽  
Skin Fold ◽  
Fat Thickness ◽  
Significant Regression ◽  
Cutaneous Vasoconstriction

Human cold adaptation was studied by comparing maximal body insulation [ I = (rectal temp. – skin temp.) /rate of skin heat loss] of Korean diving women to insulation of Korean nondiving men and women and American men and women. Appropriate measurements were made during immersion in a constant-temperature bath cool enough to induce maximal cutaneous vasoconstriction without shivering. Subcutaneous fat was estimated from measurements of skin-fold thickness. Within each racial group there is a significant regression of I on fat thickness. Koreans had a significantly greater I than Americans of comparable fat thickness. Korean diving women had the same I as nondivers of comparable fat thickness. Korean women had significantly greater I than Korean men due, we believe, to thicker subcutaneous fat. This may be the reason why women and not men engage in diving. The only evidence for cold adaptation among diving women was their ability to withstand colder water immersion without shivering. Submitted on March 22, 1962

Sympathetic nonnoradrenergic cutaneous vasoconstriction in women is associated with reproductive hormone status

2002 ◽  
Vol 282 (1) ◽  
pp. H264-H272 ◽  
Author(s):  
Dan P. Stephens ◽  
Lee Ann T. Bennett ◽  
Ken Aoki ◽  
Wojciech A. Kosiba ◽  
Nisha Charkoudian ◽  
...  
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Contraceptive Use ◽  
Intradermal Injection ◽  
Reproductive Hormones ◽  
Whole Body ◽  
Reproductive Hormone ◽  
Doppler Flowmetry ◽  
Hormone Status ◽  
Cutaneous Vasoconstriction

We tested whether a nonnoradrenergic component of reflex vasoconstriction of skin blood flow (SkBF) is sensitive to female reproductive hormones. Six women taking oral contraceptives underwent whole-body cooling during high-hormone (HH) and low-hormone (LH) phases of oral contraceptive use. SkBF was monitored by laser Doppler flowmetry (LDF) at sites treated by intradermal injection of yohimbine-propranolol (5 mM and 1 mM; YOPR) to block the effects of norepinephrine (NE) or at saline (Sal) control sites. Mean arterial pressure (MAP) was measured with the use of the Penaz method. Cutaneous vascular conductance (CVC = LDF/mean arterial pressure) was expressed as a percentage of baseline. Whole body skin temperature was decreased from 34 to 31°C in HH and LH. In both HH and LH, CVC at Sal-treated sites was reduced during cooling (CVC = 53.1 ± 8.6% and 54.4 ± 4.2%, both P < 0.05). In HH, CVC at YOPR sites was reduced during cooling (78.8 ± 3.6%, P < 0.05). In contrast, CVC at YOPR sites was not reduced significantly during cooling in LH (CVC = 95.9 ± 2.8%, P > 0.05). Across phases, CVC at YOPR sites during cooling was significantly different ( P < 0.05). After cooling, the effects of NE at YOPR sites were completely blocked. These data indicate that a nonnoradrenergic mechanism of reflex cutaneous vasoconstriction is present in women and is associated with reproductive hormone status.

Epidermal thermal conductivity and stratum corneum hydration in cat footpad

1975 ◽  
Vol 228 (6) ◽  
pp. 1903-1908 ◽  
Author(s):  
KR Holmes ◽  
T Adams
Keyword(s):  
Thermal Conductivity ◽  
Stratum Corneum ◽  
Water Content ◽  
Skin Surface ◽  
Blocking Agent ◽  
Eccrine Sweat Gland ◽  
Dermoepidermal Junction ◽  
Stratum Corneum Hydration ◽  
Cutaneous Vasoconstriction ◽  
Stratum Corneum Water Content

Epidermal thermal conductivity (k) was calculated for the cat footpad by measuringtransepidermal heat flux and temperature gradient ( inverted question markT) while changes in stratum corneum water content were produced by "internal hydration" (IH; eccrine sweat gland activity by nerve stimulation) or by "external hydration" (HH; exposure to air saturated with water vapor). In some experiments, cutaneous vasoconstriction accompanying IH was prevented by an alpha-adrenergic receptor blocking agent, phenoxybenzamine (POB), 3.52 mg/kg iv. For dry skin k=0.167 plus or minus 0.023 (SE) W.m (-1) degree C (-1). With and without POB, IH produced 49.5% and 17.2% increases in k, respectively; HH after IH did not increase k more. With POB, IH increased k more than did HH alone (49.5% and 15.5%, respectively) and at a higher rate (4.22 times 10 minus 3 and 0.63 times 10 minus 3 W.m minus 1.degree C minus 1. min minus 1, respectively.) As k increased, usually deltaT decreased. Increasing k and decreasing deltaT with skin hydration explain the phenominon that air temperature is felt to be lower the more humid a cold exposure, since the temperature of thermoreceptors at the dermoepidermal junction is closer to that of the skin surface when the corneum is hydrated than when it has a low water content.

scholarly journals Pharmacological curve fitting to analyze cutaneous adrenergic responses

2011 ◽  
Vol 111 (6) ◽  
pp. 1703-1709 ◽  
Author(s):  
Megan M. Wenner ◽  
Thad E. Wilson ◽  
Scott L. Davis ◽  
Nina S. Stachenfeld
Keyword(s):  
Dose Response ◽  
Curve Fitting ◽  
Repeated Measures ◽  
Nonlinear Modeling ◽  
Response Curves ◽  
Data Set ◽  
Sigmoidal Model ◽  
Dose Response Curves ◽  
Cutaneous Vasoconstriction

Although dose-response curves are commonly used to describe in vivo cutaneous α-adrenergic responses, modeling parameters and analyses methods are not consistent across studies. The goal of the present investigation was to compare three analysis methods for in vivo cutaneous vasoconstriction studies using one reference data set. Eight women (22 ± 1 yr, 24 ± 1 kg/m2) were instrumented with three cutaneous microdialysis probes for progressive norepinephrine (NE) infusions (1 × 10−8, 1 × 10−6, 1 × 10−5, 1 × 10−4, and 1 × 10−3 logM). NE was infused alone, co-infused with NG-monomethyl-l-arginine (l-NMMA, 10 mM) or Ketorolac tromethamine (KETO, 10 mM). For each probe, dose-response curves were generated using three commonly reported analyses methods: 1) nonlinear modeling without data manipulation, 2) nonlinear modeling with data normalization and constraints, and 3) percent change from baseline without modeling. Not all data conformed to sigmoidal dose-response curves using analysis 1, whereas all subjects' curves were modeled using analysis 2. When analyzing only curves that fit the sigmoidal model, NE + KETO induced a leftward shift in ED50 compared with NE alone with analyses 1 and 2 ( F test, P < 0.05) but only tended to shift the response leftward with analysis 3 (repeated-measures ANOVA, P = 0.08). Neither maximal vasoconstrictor capacity (Emax) in analysis 1 nor %change CVC change from baseline in analysis 3 were altered by blocking agents. In conclusion, although the overall detection of curve shifts and interpretation was similar between the two modeling methods of curve fitting, analysis 2 produced more sigmoidal curves.

Cutaneous and skeletal muscle vascular responses to hypothermia

1981 ◽  
Vol 240 (6) ◽  
pp. H868-H873 ◽  
Author(s):  
T. C. Major ◽  
J. M. Schwinghamer ◽  
S. Winston
Keyword(s):  
Skeletal Muscle ◽  
Vascular Resistance ◽  
Sympathetic Nerves ◽  
Local Cooling ◽  
Right Heart ◽  
Vascular Responses ◽  
External Cooling ◽  
Vasoconstrictor Response ◽  
The Right ◽  
Cutaneous Vasoconstriction

Vascular resistance and capacitance were studied in innervated or denervated canine forelimbs. Hypothermia (38-28 degrees C) was induced systemically, by external cooling of blood which returned to the right heart, or locally, by cooling blood perfusing the forelimb. Systemic cooling to 33 and then to 28 degrees C elicited significant decreases in limb weight with substantial increases in both skin and skeletal muscle vascular resistances. Acute denervation of the forelimbs attenuated both the fall in limb weight and increase in skin vascular resistance associated with cooling. These data support the contention that cutaneous vasoconstriction during systemic cooling is mediated primarily by sympathetic nerves, whereas skeletal muscle vasoconstriction is mediated primarily by circulating hormones. Local cooling elicited skin and skeletal muscle vascular dilation at 33 degrees C in both innervated and denervated forelimbs whereas either no change or a slight increase in skin and skeletal muscle vascular resistance resulted upon local cooling to 28 degrees C, perhaps due to the inhibition of Na+ - K+ - ATPase activity and/or a rise in blood viscosity. The locally induced vasodilation was found to override the powerful vasoconstrictor response caused by systemic cooling. The vasodilation is considered active rather than passive, because the increase in forelimb weight and decreases in forelimb vascular resistances occurred in the denervated as well as innervated limbs.

Cutaneous vasoconstriction in conscious rabbits during alerting responses detected by hippocampal theta-rhythm

1997 ◽  
Vol 272 (1) ◽  
pp. R208-R216 ◽  
Author(s):  
Y. H. Yu ◽  
W. W. Blessing
Keyword(s):  
Skeletal Muscle ◽  
Heart Rate ◽  
Blood Flow ◽  
Arterial Pressure ◽  
Theta Rhythm ◽  
Renal Flow ◽  
Conscious Rabbits ◽  
Hippocampal Theta ◽  
Electroencephalogram Eeg ◽  
Cutaneous Vasoconstriction

We determined whether alerting stimuli cause cutaneous vasoconstriction in conscious rabbits. We compared ear blood flow with renal, mesenteric, and femoral flows at rest and in response to nonnoxious alerting stimuli, which induced theta-rhythm (4-9 Hz) in the simultaneously recorded hippocampal electroencephalogram (EEG). theta-Inducing stimuli (e.g., whistles and fur touches) reduced ear flow by 95 +/- 6%, commencing 1-2 s after the EEG change and lasting 45 s. Renal flow did not significantly change with alerting stimuli, mesenteric and femoral flows slightly decreased, arterial pressure transiently rose (+10 +/- 3 mmHg), and heart rate fell (+43 +/- 9 beats/min). At rest, the coefficient of variation for ear flow (62 +/- 6%) was greater than for other flows (P < 0.01). Phentolamine (1 mg/kg iv) reduced this coefficient to 29 +/- 4% (P < 0.01). Our study demonstrates that alerting responses in conscious rabbits are associated with selective cutaneous vasoconstriction, without increase in flow to skeletal muscle.

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