Control of skin blood flow, sweating, and heart rate: role of skin vs. core temperature.

1974 ◽  
Vol 36 (6) ◽  
pp. 726-733 ◽  
Author(s):  
C R Wyss ◽  
G L Brengelmann ◽  
J M Johnson ◽  
L B Rowell ◽  
M Niederberger
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Core Temperature ◽  
Skin Blood Flow

Haemodynamic role of vasopressin released during Finnish sauna

1986 ◽  
Vol 112 (2) ◽  
pp. 166-171 ◽  
Author(s):  
J. P. Bussien ◽  
R. C. Gaillard ◽  
J. Nussberger ◽  
B. Waeber ◽  
K. G. Hofbauer ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Skin Blood Flow ◽  
Plasma Osmolality ◽  
Plasma Renin ◽  
Plasma Norepinephrine ◽  
Hot Air ◽  
Simultaneous Change

Abstract. The effect of vasopressin released during Finnish sauna on blood pressure, heart rate and skin blood flow was investigated in 12 healthy volunteers. Exposure to the hot air decrease body weight by 0.6 to 1.25 kg (mean = 0.8 kg, P < 0.001). One hour after the end of the sauna sessions, plasma vasopressin was higher (1.7 ± 0.2 pg/ml, P < 0.01 mean ± sem) than before the sauna (1.0 ± 0.1 pg/ml). No simultaneous change in plasma osmolality, plasma renin activity, plasma norepinephrine, epinephrine, cortisol, aldosterone, beta-endorphin and metenkephalin levels was observed. Despite the slight sauna-induced elevation in circulating vasopressin, intravenous injection of the specific vascular vasopressin antagonist d(CH2)5Tyr-(Me)AVP (5 μg/kg) 1 h after the sauna had no effect on blood pressure, heart rate or skin blood flow. These data suggest that vasopressin released into the circulation during a sauna session reaches concentrations which are not high enough to interfere directly with vascular tone.

scholarly journals Computational Analysis of Coronary Blood Flow: The Role of Asynchronous Pacing and Arrhythmias

Mathematics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1205
Author(s):  
Timur Gamilov ◽  
Philipp Kopylov ◽  
Maria Serova ◽  
Roman Syunyaev ◽  
Andrey Pikunov ◽  
...  
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Coronary Blood Flow ◽  
Long Qt Syndrome ◽  
Premature Ventricular Contraction ◽  
Cardiac Pacing ◽  
Long Qt ◽  
Computational Evaluation ◽  
Qt Syndrome

In this work we present a one-dimensional (1D) mathematical model of the coronary circulation and use it to study the effects of arrhythmias on coronary blood flow (CBF). Hydrodynamical models are rarely used to study arrhythmias’ effects on CBF. Our model accounts for action potential duration, which updates the length of systole depending on the heart rate. It also includes dependency of stroke volume on heart rate, which is based on clinical data. We apply the new methodology to the computational evaluation of CBF during interventricular asynchrony due to cardiac pacing and some types of arrhythmias including tachycardia, bradycardia, long QT syndrome and premature ventricular contraction (bigeminy, trigeminy, quadrigeminy). We find that CBF can be significantly affected by arrhythmias. CBF at rest (60 bpm) is 26% lower in LCA and 22% lower in RCA for long QT syndrome. During bigeminy, trigeminy and quadrigeminy, respectively, CBF decreases by 28%, 19% and 14% with respect to a healthy case.

Hypothalamic paraventricular nucleus is critical for renal vasoconstriction elicited by elevations in body temperature

2008 ◽  
Vol 294 (2) ◽  
pp. F309-F315 ◽  
Author(s):  
Joo Lee Cham ◽  
Emilio Badoer
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Renal Blood Flow ◽  
Core Temperature ◽  
Paraventricular Nucleus ◽  
Hypothalamic Paraventricular Nucleus ◽  
Body Core Temperature ◽  
Control Group ◽  
Body Core

Redistribution of blood from the viscera to the peripheral vasculature is the major cardiovascular response designed to restore thermoregulatory homeostasis after an elevation in body core temperature. In this study, we investigated the role of the hypothalamic paraventricular nucleus (PVN) in the reflex decrease in renal blood flow that is induced by hyperthermia, as this brain region is known to play a key role in renal function and may contribute to the central pathways underlying thermoregulatory responses. In anesthetized rats, blood pressure, heart rate, renal blood flow, and tail skin temperature were recorded in response to elevating body core temperature. In the control group, saline was microinjected bilaterally into the PVN; in the second group, muscimol (1 nmol in 100 nl per side) was microinjected to inhibit neuronal activity in the PVN; and in a third group, muscimol was microinjected outside the PVN. Compared with control, microinjection of muscimol into the PVN did not significantly affect the blood pressure or heart rate responses. However, the normal reflex reduction in renal blood flow observed in response to hyperthermia in the control group (∼70% from a resting level of 11.5 ml/min) was abolished by the microinjection of muscimol into the PVN (maximum reduction of 8% from a resting of 9.1 ml/min). This effect was specific to the PVN since microinjection of muscimol outside the PVN did not prevent the normal renal blood flow response. The data suggest that the PVN plays an essential role in the reflex decrease in renal blood flow elicited by hyperthermia.

Peripheral blood flow during rewarming from mild hypothermia in humans

1985 ◽  
Vol 58 (1) ◽  
pp. 4-13 ◽  
Author(s):  
G. K. Savard ◽  
K. E. Cooper ◽  
W. L. Veale ◽  
T. J. Malkinson
Keyword(s):  
Blood Flow ◽  
Core Temperature ◽  
Skin Blood Flow ◽  
Cold Water ◽  
Mild Hypothermia ◽  
Muscle Blood Flow ◽  
Venous Occlusion ◽  
Warm Bath ◽  
Peripheral Blood Flow ◽  
Deep Body Temperature

During the initial stages of rewarming from hypothermia, there is a continued cooling of the core, or after-drop in temperature, that has been attributed to the return of cold blood due to peripheral vasodilatation, thus causing a further decrease of deep body temperature. To examine this possibility more carefully, subjects were immersed in cold water (17 degrees C), and then rewarmed from a mildly hypothermic state in a warm bath (40 degrees C). Measurements of hand blood flow were made by calorimetry and of forearm, calf, and foot blood flows by straingauge venous occlusion plethysmography at rest (Ta = 22 degrees C) and during rewarming. There was a small increase in skin blood flow during the falling phase of core temperature upon rewarming in the warm bath, but none in foot blood flow upon rewarming at room air, suggesting that skin blood flow seems to contribute to the after-drop, but only minimally. Limb blood flow changes during this phase suggest that a small muscle blood flow could also have contributed to the after-drop. It was concluded that the after-drop of core temperature during rewarming from mild hypothermia does not result from a large vasodilatation in the superficial parts of the periphery, as postulated. The possible contribution of mechanisms of heat conduction, heat convection, and cessation of shivering thermogenesis were discussed.

Neuropeptide Y and Y1-receptor agonists increase blood flow through arteriovenous anastomoses in rat tail

1998 ◽  
Vol 85 (1) ◽  
pp. 301-309 ◽  
Author(s):  
Martha E. Heath
Keyword(s):  
Blood Flow ◽  
Neuropeptide Y ◽  
Core Temperature ◽  
Skin Blood Flow ◽  
Arteriovenous Anastomoses ◽  
Total Blood ◽  
Y1 Receptor ◽  
Pentobarbital Sodium Anesthesia ◽  
Total Blood Flow ◽  
Rat Tail

The purpose of this study was to characterize neuropeptide Y (NPY)-induced vasodilation in the rat tail. Sterile surgical technique was used (with pentobarbital sodium anesthesia) to equip rats with a jugular catheter and a blind-ended thermocouple reentrant tube next to the carotid artery. Tail skin and core temperature were measured with thermocouples during experiments. Tail skin blood flow was monitored with a laser Doppler flowmeter, and tail total blood flow and volume were measured with plethysmography. After baseline data were collected, saline, NPY (16, 32, 64, and 128 μg/kg), [Leu31Pro34]NPY (63.25 μg/kg), or NPY[13–36] (44.7 μg/kg) was administered intravenously. Tail total blood flow, volume, and tail skin temperature increased, whereas tail skin blood flow and core temperature decreased in response to both NPY- and the Y1-receptor agonist [Leu31Pro34]NPY but not in response to saline or NPY[13–36]. Studies conducted with the use of color microspheres demonstrated that arteriovenous anastomoses are involved in this NPY-induced vasodilation.

Age alters regional distribution of blood flow during moderate-intensity exercise

1995 ◽  
Vol 79 (4) ◽  
pp. 1112-1119 ◽  
Author(s):  
W. L. Kenney ◽  
C. W. Ho
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Renal Blood Flow ◽  
Skin Blood Flow ◽  
Forearm Blood Flow ◽  
Regional Distribution ◽  
Splanchnic Blood Flow ◽  
Moderate Intensity ◽  
Plasma Norepinephrine ◽  
Moderate Intensity Exercise

During dynamic exercise in warm environments, requisite increases in skin and active muscle blood flows are supported by increasing cardiac output (Qc) and redistributing flow away from splanchnic and renal circulations. To examine the effect of age on these responses, six young (Y; 26 +/- 2 yr) and six older (O; 64 +/- 2 yr) men performed upright cycle exercise at 35 and 60% of peak O2 consumption (VO2peak) in 22 and 36 degrees C environments. To further isolate age, the two age groups were closely matched for VO2peak, weight, surface area, and body composition. Measurements included heart rate, Qc (CO2 rebreathing), skin blood flow (from increases in forearm blood flow (venous occlusion plethysmography), splanchnic blood flow (indocyanine green dilution), renal blood flow (p-amino-hippurate clearance), and plasma norepinephrine concentration. There were no significant age differences in Qc; however, in both environments the O group maintained Qc at a higher stroke volume and lower heart rate. At 60% VO2peak, forearm blood flow was significantly lower in the O subjects in each environment. Splanchnic blood flow fell (by 12–14% in both groups) at the lower intensity, then decreased to a greater extent at 60% VO2peak in Y than in O subjects (e.g., -45 +/- 2 vs. -33 +/- 3% for the hot environment, P < 0.01). Renal blood flow was lower at rest in the O group, remained relatively constant at 35% VO2peak, then decreased by 20–25% in both groups at 60% VO2peak. At 60% VO2peak, 27 and 37% more total blood flow was redistributed away from these two circulations in the Y than in the O group at 22 and 36 degrees, respectively. It was concluded that the greater increase in skin blood flow in Y subjects is partially supported by a greater redistribution of blood flow away from splanchnic and renal vascular beds.

The Role of Nitric Oxide in Skin Blood Flow Increases Due to Vibration in Healthy Adults and Adults with Type 2 Diabetes

2009 ◽  
Vol 11 (1) ◽  
pp. 39-43 ◽  
Author(s):  
Colleen Maloney-Hinds ◽  
Jerrold S. Petrofsky ◽  
Grenith Zimmerman ◽  
David A. Hessinger
Keyword(s):  
Nitric Oxide ◽  
Type 2 Diabetes ◽  
Blood Flow ◽  
Skin Blood Flow ◽  
Healthy Adults

Reactivity of skin blood flow and heart rate to external thermal stimulation in anencephaly

1997 ◽  
Vol 86 (4) ◽  
pp. 426-427 ◽  
Author(s):  
T Jahnukainen ◽  
A Lindqvist ◽  
T Äärimaa ◽  
P Kero ◽  
I Välimäki
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Skin Blood Flow ◽  
Thermal Stimulation

Stroke volume during exercise: interaction of environment and hydration

2000 ◽  
Vol 278 (2) ◽  
pp. H321-H330 ◽  
Author(s):  
José González-Alonso ◽  
Ricardo Mora-Rodríguez ◽  
Edward F. Coyle
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Body Weight ◽  
Stroke Volume ◽  
Blood Volume ◽  
Skin Blood Flow ◽  
Body Weight Loss ◽  
Cold Environment ◽  
Esophageal Temperature ◽  
Trained Subjects

Euhydrated and dehydrated subjects exercised in a hot and a cold environment with our aim to identify factors that relate to reductions in stroke volume (SV). We hypothesized that reductions in SV with heat stress are related to the interaction of several factors rather than the effect of elevated skin blood flow. Eight male endurance-trained cyclists [maximal O2 consumption (V˙o 2 max) 4.5 ± 0.1 l/min; means ± SE] cycled for 30 min (72%V˙o 2 max) in the heat (H; 35°C) or the cold (C; 8°C) when euhydrated or dehydrated by 1.5, 3.0, or 4.2% of their body weight. When euhydrated, SV and esophageal temperature (Tes 38.2–38.3°C) were similar in H and C, whereas skin blood flow was much higher in H vs. C (365 ± 64% higher; P < 0.05). With each 1% body weight loss, SV declined 6.4 ± 1.3 ml (4.8%) in H and 3.4 ± 0.4 ml (2.5%) in C, whereas Tes increased 0.21 ± 0.02 and 0.10 ± 0.02°C in H and C, respectively ( P < 0.05). However, reductions in SV were not associated with increases in skin blood flow. The reduced SV was highly associated with increased heart rate and reduced blood volume in both H ( R = 0.96; P < 0.01) and C ( R = 0.85; P < 0.01). In conclusion, these results suggest that SV is maintained in trained subjects during exercise in euhydrated conditions despite large differences in skin blood flow. Furthermore, the lowering of SV with dehydration appears largely related to increases in heart rate and reductions in blood volume.

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