Seasonal Variations in Cyclic GMP Response on Whole-Body Cooling in Women with Primary Raynaud's Phenomenon

1997 ◽  
Vol 93 (2) ◽  
pp. 175-179 ◽  
Author(s):  
Jerzy Leppert ◽  
Åsa Ringqvist ◽  
Johan Ahlner ◽  
Urban Myrdal ◽  
Marie-Louise Walker-Engström ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Seasonal Variation ◽  
Cyclic Gmp ◽  
Cold Exposure ◽  
Raynaud’S Phenomenon ◽  
Whole Body ◽  
Healthy Women ◽  
Primary Raynaud’S Phenomenon ◽  
Body Cooling ◽  
Whole Body Cooling

1. Primary Raynaud's phenomenon (PRP) is characterized by increased vasoconstrictor tone that develops during exposure to cold. The symptoms are most pronounced during the winter months with low outdoor temperature. The l-arginine—nitric oxide (NO)—cyclic GMP (cGMP) pathway plays an important role in counteracting vasospasm. The aim of the present study was to investigate if the venous cGMP response to whole-body cooling in women with PRP varied with the season of the year. 2. The study was performed as an open parallel-group comparison between women with PRP and healthy female controls during the winter months of February 1994 and 1995 and in the summer month of August 1994. Blood samples were drawn just before and 40 min after whole-body cooling. 3. There were no significant changes in venous cGMP after whole-body cooling in women with PRP during the winter months of February 1994 and 1995. Cold exposure in the summer month of August resulted, however, in a significant increase in venous cGMP (P < 0.01). In contrast, the healthy women responded with a significant increase in venous cGMP on all three test occasions: February 1994 (P < 0.05), August 1994 (P < 0.05) and February 1995 (P < 0.01) 4. A seasonal variation in venous cGMP response to whole-body cooling was observed only in women with PRP. Healthy women responded to cold exposure with an increase in venous cGMP during summer and winter, whereas females with PRP showed an increase only during summer. Results from the present study might indicate seasonal variation in the regulation of constitutive nitric oxide synthetase in women with PRP, which may contribute to new therapeutic approaches.

Non-Invasive Investigation of Endothelium-Dependent Dilatation of the Brachial Artery in Women with Primary Raynaud's Phenomenon

1998 ◽  
Vol 94 (3) ◽  
pp. 239-243 ◽  
Author(s):  
Åsa Ringqvist ◽  
Tommy Jonason ◽  
Jerzy Leppert ◽  
Ivar Ringqvist
Keyword(s):  
Brachial Artery ◽  
Room Temperature ◽  
Raynaud’S Phenomenon ◽  
Raynaud's Phenomenon ◽  
Whole Body ◽  
Significant Difference ◽  
Flow Mediated Dilatation ◽  
Primary Raynaud’S Phenomenon ◽  
Body Cooling ◽  
Whole Body Cooling

1. Primary Raynaud's phenomenon is characterized by white fingers and toes with impaired perfusion in response to cold or emotional stress. The aetiology has not been clarified. In previous studies we have demonstrated a season-linked inability in women with primary Raynaud's phenomenon to raise their plasma cGMP levels in response to whole-body cooling, suggesting a dysfunction of the l-arginine—NO—cGMP pathway. To further elucidate the possibility of such a defect in patients with primary Raynaud's phenomenon, we determined flow-mediated dilatation of the brachial artery. 2. Twenty-two premenopausal, non-smoking women with primary Raynaud's phenomenon (mean age 39 ± 8 years) and 23 healthy controls (mean age 41 ± 7 years) were studied during two winter weeks. The diameter of the right arm brachial artery was measured by high resolution ultrasonography, at rest and during reactive hyperaemia. The investigation was conducted both with the participants at rest at room temperature and after 40 min of whole-body cooling. 3. Both study groups showed a marked attenuation of flow-mediated dilatation during whole-body cooling, which could partly but not solely be explained by a decreased shear rate. There was, however, no significant difference in flow-mediated diameter (D) increase (% flow-mediated dilatation; ΔD/D × 100) between primary Raynaud's phenomenon and controls, either at room temperature (7.8 ± 0.8 and 9.0 ± 0.8) or in response to whole-body cooling (3.8 ± 1.2 and 4.4 ± 0.7). 4. Thus, whole-body cooling markedly impairs flow-mediated dilatation in women. Flow-mediated dilatation is, however, not decreased in women with primary Raynaud's phenomenon at room temperature or during whole-body cooling, indicating that this particular aspect of endothelial function is not impaired in this setting.

scholarly journals The nitric oxide dependence of cutaneous microvascular function to independent and combined hypoxic cold exposure

2020 ◽  
Vol 129 (4) ◽  
pp. 947-956
Author(s):  
Josh T. Arnold ◽  
Alex B. Lloyd ◽  
Stephen J. Bailey ◽  
Tomomi Fujimoto ◽  
Ryoko Matsutake ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Nitrite Reduction ◽  
Whole Body ◽  
Local Cooling ◽  
Cutaneous Reflex ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
Oxide Removal ◽  
Oxide Synthase

When separated from local cooling, whole body cooling elicited cutaneous reflex vasoconstriction via mechanisms independent of nitric oxide removal. Hypoxia elicited cutaneous vasodilatation via mechanisms mediated primarily by nitric oxide synthase, rather than xanthine oxidase-mediated nitrite reduction. Cold-induced vasoconstriction was blunted by the opposing effect of hypoxic vasodilatation, whereas the underpinning mechanisms did not interrelate in the absence of local cooling. Full vasoconstriction was restored with nitric oxide synthase inhibition.

Effects of cold exposure and exercise in a wet, cold antarctic climate

1965 ◽  
Vol 20 (3) ◽  
pp. 417-422 ◽  
Author(s):  
G. M. Budd
Keyword(s):  
Physical Fitness ◽  
Cold Exposure ◽  
Subcutaneous Fat ◽  
Whole Body ◽  
Finger Temperature ◽  
Arterial Blood ◽  
Before And After ◽  
Tissue Insulation ◽  
Body Cooling ◽  
Whole Body Cooling

Six men were studied before and after 6 weeks of strenuous outdoor work and cold exposure—often in wet clothing—on Heard Island in the Antarctic. Physical fitness increased significantly, while subcutaneous fat and arterial blood pressure decreased significantly. The response of rectal temperature and shivering to a 2-hr period of whole-body cooling did not change significantly (although shivering tended to decrease), suggesting that the reduction in insulation caused by loss of fat was balanced by an increase in the insulation of other tissues. Finger temperature fell more rapidly, there was less cold vasodilatation, and the gradient of skin temperature between elbow and finger increased significantly, suggesting that heat was conserved by means of countercurrent heat exchanges and enhanced vasoconstriction. Discomfort from cold did not change. These results support those of a previous study at Mawson, Antarctica. Frostbite of one subject's hands, which grossly impaired touch sensation and caused marked intolerance to cold, produced no obvious changes in the response to cold of finger temperature. vasomotor adaptation to cold; cold vasodilatation; tissue insulation; subcutaneous fat; shivering; subjective responses to cold; frostbite sequelae; finger temperature before and after cold injury; physical fitness; acclimatization to cold Submitted on September 8, 1964

scholarly journals Distribution and Severity of Hypoxic-Ischemic Lesions on Brain MRI Following Therapeutic Cooling: Selective Head Versus Whole Body Cooling

2011 ◽  
Vol 70 ◽  
pp. 722-722
Author(s):  
S Sarkar ◽  
J R Bapuraj ◽  
S M Donn ◽  
I Bhagat ◽  
J D Barks
Keyword(s):  
Brain Mri ◽  
Whole Body ◽  
Body Cooling ◽  
Whole Body Cooling

The Cooling Power of Pigeon Wings

1991 ◽  
Vol 155 (1) ◽  
pp. 193-202 ◽  
Author(s):  
ALBERT CRAIG ◽  
JACQUES LAROCHELLE
Keyword(s):  
Body Temperature ◽  
Heat Production ◽  
Heat Dissipation ◽  
Experimental System ◽  
Whole Body ◽  
Cooling Power ◽  
Wind Speeds ◽  
Maximum Value ◽  
Body Cooling ◽  
Whole Body Cooling

The rate of heat loss through the stretched wings (Hwings) was studied in resting pigeons preheated to a body temperature (43.7°C) within the range of those recorded during flight. The experimental system was designed to allow the calculation of Hwings from the increase in whole-body cooling rates resulting from exposure of the wings to various wind speeds (0–50 km h−1) at 23°C. The maximum value of HWings was 3.8 W, less than twice the heat production of a resting pigeon. This indicates that the contribution of the wings to heat dissipation during flight may not be nearly as important as has been supposed. At low windspeeds (0–12.5 km h−1), HWings corresponded to about 40% of the resting rate of heat production, and this value is discussed in connection with the various wing postures observed in hyperthermic birds.

The effect of whole body cooling in asphyxiated neonates with resource limitation: Challenges and experience

2018 ◽  
Vol 7 (1) ◽  
pp. 7
Author(s):  
Rahul Sinha ◽  
K Venkatnarayan ◽  
Vandana Negi ◽  
Kirandeep Sodhi ◽  
BM John
Keyword(s):  
Resource Limitation ◽  
Whole Body ◽  
Body Cooling ◽  
Whole Body Cooling

scholarly journals An In Vivo Assessment of Regional Brain Temperature during Whole-Body Cooling for Neonatal Encephalopathy

2020 ◽  
Vol 220 ◽  
pp. 73-79.e3
Author(s):  
Tai-Wei Wu ◽  
Jessica L. Wisnowski ◽  
Robert F. Geisler ◽  
Aaron Reitman ◽  
Eugenia Ho ◽  
...  
Keyword(s):  
Brain Temperature ◽  
Whole Body ◽  
Neonatal Encephalopathy ◽  
Regional Brain ◽  
Body Cooling ◽  
Whole Body Cooling ◽  
In Vivo Assessment
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