Does local heating-induced nitric oxide production attenuate vasoconstrictor responsiveness to lower body negative pressure in human skin?

2007 ◽  
Vol 102 (5) ◽  
pp. 1839-1843 ◽  
Author(s):  
David A. Low ◽  
Manabu Shibasaki ◽  
Scott L. Davis ◽  
David M. Keller ◽  
Craig G. Crandall
Keyword(s):  
Nitric Oxide ◽  
Negative Pressure ◽  
Lower Body Negative Pressure ◽  
Local Heating ◽  
Ringer Solution ◽  
No Production ◽  
Lower Body ◽  
Forearm Skin ◽  
Per Se ◽  
Cutaneous Vascular Conductance

We tested the hypothesis that local heating-induced nitric oxide (NO) production attenuates cutaneous vasoconstrictor responsiveness. Eleven subjects (6 men, 5 women) had four microdialysis membranes placed in forearm skin. Two membranes were perfused with 10 mM of NG-nitro-l-arginine (l-NAME) and two with Ringer solution (control), and all sites were locally heated to 34°C. Subjects then underwent 5 min of 60-mmHg lower body negative pressure (LBNP). Two sites (a control and an l-NAME site) were then heated to 39°C, while the other two sites were heated to 42°C. At the l-NAME sites, skin blood flow was elevated using 0.75–2 mg/ml of adenosine in the perfusate solution (Adn + l-NAME) to a similar level relative to control sites. Subjects then underwent another 5 min of 60-mmHg LBNP. At 34°C, cutaneous vascular conductance (CVC) decreased (Δ) similarly at both control and l-NAME sites during LBNP (Δ7.9 ± 3.0 and Δ3.4 ± 0.8% maximum, respectively; P > 0.05). The reduction in CVC to LBNP was also similar between control and Adn + l-NAME sites at 39°C (control Δ11.4 ± 2.5 vs. Adn + l-NAME Δ7.9 ± 2.0% maximum; P > 0.05) and 42°C (control Δ1.9 ± 2.7 vs. Adn + l-NAME Δ 4.2 ± 2.7% maximum; P > 0.05). However, the decrease in CVC at 42°C, regardless of site, was smaller than at 39°C ( P < 0.05). These results do not support the hypothesis that local heating-induced NO production attenuates cutaneous vasoconstrictor responsiveness during high levels of LBNP. However, elevated local temperature, per se, attenuates cutaneous vasoconstrictor responsiveness to LBNP, presumably through non-nitric oxide mechanisms.

scholarly journals Tempol improves cutaneous thermal hyperemia through increasing nitric oxide bioavailability in young smokers

2014 ◽  
Vol 306 (11) ◽  
pp. H1507-H1511 ◽  
Author(s):  
Naoto Fujii ◽  
Vienna E. Brunt ◽  
Christopher T. Minson
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Vascular Function ◽  
Local Heating ◽  
Young Male ◽  
Ringer Solution ◽  
No Production ◽  
Daily Consumption ◽  
Arterial Blood ◽  
Young Smokers

We recently found that young cigarette smokers display cutaneous vascular dysfunction relative to nonsmokers, which is partially due to reduced nitric oxide (NO) synthase (NOS)-dependent vasodilation. In this study, we tested the hypothesis that reducing oxidative stress improves NO bioavailability, enhancing cutaneous vascular function in young smokers. Ten healthy young male smokers, who had smoked for 6.3 ± 0.7 yr with an average daily consumption of 9.1 ± 0.7 cigarettes, were tested. Cutaneous vascular conductance (CVC) during local heating to 42°C at a rate of 0.1°C/s was evaluated as laser-Doppler flux divided by mean arterial blood pressure and normalized to maximal CVC, induced by local heating to 44°C plus sodium nitroprusside administration. We evaluated plateau CVC during local heating, which is known to be highly dependent on NO, at four intradermal microdialysis sites with 1) Ringer solution (control); 2) 10 μM 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (tempol), a superoxide dismutase mimetic; 3) 10 mM Nω-nitro-l-arginine (l-NNA), a nonspecific NOS inhibitor; and 4) a combination of 10 μM tempol and 10 mM l-NNA. Tempol increased plateau CVC compared with the Ringer solution site (90.0 ± 2.3 vs. 77.6 ± 3.9%maximum, P = 0.028). Plateau CVC at the combination site (56.8 ± 4.5%maximum) was lower than the Ringer solution site ( P < 0.001) and was not different from the l-NNA site (55.1 ± 4.6%maximum, P = 0.978), indicating the tempol effect was exclusively NO dependent. These data suggest that in young smokers, reducing oxidative stress improves cutaneous thermal hyperemia to local heating by enhancing NO production.

Cardiovascular Responses to Maximal Graded and Acute Lower Body Negative Pressure

2010 ◽  
Vol 18 (1) ◽  
pp. 27-42 ◽  
Author(s):  
Juliane P. Hernandez ◽  
Kristin Roever ◽  
Tonya Seed
Keyword(s):  
Heart Rate ◽  
Negative Pressure ◽  
Orthostatic Intolerance ◽  
Lower Body Negative Pressure ◽  
Cardiovascular Responses ◽  
Tolerance Index ◽  
Lower Body ◽  
Age Related ◽  
Per Se ◽  
Blood Pressure Responses

This investigation attempted to determine whether heart-rate and blood pressure responses to maximal acute lower body negative pressure (LBNP) are exacerbated compared with maximal graded LBNP in active older (n= 9, 70 ± 7 yr) and endurance-trained younger (n= 10, 23 ± 3 yr) individuals. Heart rate increased earlier during graded LBNP in the younger group (−40 mm Hg vs. tolerance) and was significantly higher than that of the older adults at the point of tolerance. Mean arterial pressure (MAP) decreased more in the older than the younger individuals during graded LBNP. LBNP-tolerance index was significantly greater in the younger group (309 ± 52 vs. 255.6 ± 48 mm Hg/min). Acute doses of LBNP elicited slower heart-rate responses in the older group. Despite these age-related differences, MAP responses were not different between groups with acute LBNP, so age per se does not appear to predispose individuals to orthostatic intolerance.

scholarly journals Sex- and limb-specific differences in the nitric oxide-dependent cutaneous vasodilation in response to local heating

2014 ◽  
Vol 307 (7) ◽  
pp. R914-R919 ◽  
Author(s):  
Anna E. Stanhewicz ◽  
Jody L. Greaney ◽  
W. Larry Kenney ◽  
Lacy M. Alexander
Keyword(s):  
Nitric Oxide ◽  
Local Heating ◽  
Ringer Solution ◽  
No Synthase ◽  
Site Assessment ◽  
Cutaneous Vasodilation ◽  
Dependent Component ◽  
Doppler Flux ◽  
Cutaneous Vascular Conductance ◽  
Nnos Inhibition

Local heating of the skin is commonly used to assess cutaneous microvasculature function. Controversy exists as to whether there are limb or sex differences in the nitric oxide (NO)-dependent contribution to this vasodilation, as well as the NO synthase (NOS) isoform mediating the responses. We tested the hypotheses that 1) NO-dependent vasodilation would be greater in the calf compared with the forearm; 2) total NO-dependent dilation would not be different between sexes within limb; and 3) women would exhibit greater neuronal NOS (nNOS)-dependent vasodilation in the calf. Two microdialysis fibers were placed in the skin of the ventral forearm and the calf of 19 (10 male and 9 female) young (23 ± 1 yr) adults for the local delivery of Ringer solution (control) or 5 mM Nω-propyl-l-arginine (NPLA; nNOS inhibition). Vasodilation was induced by local heating (42°C) at each site, after which 20 mM NG-nitro-l-arginine methyl ester (l-NAME) was perfused for within-site assessment of NO-dependent vasodilation. Cutaneous vascular conductance (CVC) was calculated as laser-Doppler flux/mean arterial pressure and normalized to maximum (28 mM sodium nitroprusside, 43°C). Total NO-dependent vasodilation in the calf was lower compared with the forearm in both sexes (Ringer: 42 ± 5 vs. 62 ± 4%; P < 0.05; NPLA: 37 ± 3 vs. 59 ± 5%; P < 0.05) and total NO-dependent vasodilation was lower in the forearm for women (Ringer: 52 ± 6 vs. 71 ± 4%; P < 0.05; NPLA: 47 ± 6 vs. 68 ± 5%; P < 0.05). NPLA did not affect total or NO-dependent vasodilation across limbs in either sex ( P > 0.05). These data suggest that the NO-dependent component of local heating-induced cutaneous vasodilation is lower in the calf compared with the forearm. Contrary to our original hypothesis, there was no contribution of nNOS to NO-dependent vasodilation in either limb during local heating.

Forearm skin and muscle vasoconstriction during lower body negative pressure

1986 ◽  
Vol 60 (5) ◽  
pp. 1535-1541 ◽  
Author(s):  
A. Tripathi ◽  
E. R. Nadel
Keyword(s):  
Blood Flow ◽  
Negative Pressure ◽  
Lower Body Negative Pressure ◽  
Venous Occlusion ◽  
Lower Body ◽  
Total Blood ◽  
Forearm Skin ◽  
The Difference ◽  
Total Blood Flow ◽  
Male Subjects

In view of conflicting reports of skeletal muscle and skin blood flow participation in baroreceptor-mediated reflexes, we studied the effects of graded lower body negative pressure (LBNP) on cutaneous and muscular components of forearm blood flow (FBF) in seven male subjects at 28 degrees C. FBF was measured by venous occlusion plethysmography and cutaneous flow by laser-Doppler velocimetry, the difference being the muscular flow. Mean FBF decreased by 39 and 56% from control at LBNP of 20 and 50 Torr, respectively. Skin flow decreased linearly with graded LBNP contributing 32% of the decrease of total blood flow at 20 Torr and then 50% of total decrease of blood flow at 50 Torr. Conversely, the decrease in muscle flow represented 68% of the total decrease at LBNP of 20 Torr and then 50% of the total decrease at LBNP of 50 Torr. We concluded that both skin and muscle circulations participate in sustained peripheral vasoconstriction during LBNP, with muscle flow achieving near maximum vasoconstriction by 20 Torr and skin showing a graded vasoconstriction to decreases in LBNP.

Neurohormonal responses to oscillatory lower body negative pressure in healthy subjects

2021 ◽  
Author(s):  
Akanksha Singh ◽  
Shival Srivastav ◽  
Kavita Yadav ◽  
Dinu S. Chandran ◽  
Ashok Kumar Jaryal ◽  
...  
Keyword(s):  
Negative Pressure ◽  
Healthy Subjects ◽  
Lower Body Negative Pressure ◽  
Lower Body

Bradykinin has no acute effect on the response of forearm blood flow to sympathetic stimulation in man

1990 ◽  
Vol 78 (4) ◽  
pp. 399-401 ◽  
Author(s):  
M. J. Cullen ◽  
J. R. Cockcroft ◽  
D. J. Webb
Keyword(s):  
Blood Flow ◽  
Angiotensin Ii ◽  
Negative Pressure ◽  
Enzyme Inhibitor ◽  
Lower Body Negative Pressure ◽  
Acute Effect ◽  
Acute Administration ◽  
Lower Body ◽  
Resistance Vessels ◽  
Sympathetic Responses

1. Six healthy male subjects received 0.9% (w/v) NaCl (saline) followed by incremental doses of bradykinin (1, 3 and 10 pmol/min), via the left brachial artery. Blood flow and the response of blood flow to lower-body negative pressure were measured in both forearms during infusion of saline and each dose of bradykinin. 2. Bradykinin produced a moderate and dose-dependent increase in blood flow in the infused, but not the non-infused, forearm. Lower-body negative pressure produced an approximately 15–20% reduction in blood flow in both forearms, and this response was unaffected by local infusion of bradykinin. 3. Bradykinin, in contrast to angiotensin II, had no acute effect on peripheral sympathetic responses to lower-body negative pressure. We conclude that, in forearm resistance vessels in man, withdrawal of angiotensin II, rather than accumulation of bradykinin, is likely to account for the attenuation of peripheral sympathetic responses after acute administration of a converting-enzyme inhibitor.

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