Document Detail


Impaired thermoregulatory cutaneous vasodilation in spontaneously hypertensive rats.
MedLine Citation:
PMID:  8002516     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Spontaneously hypertensive rats (SHR) are more suitable to heat stroke than are normotensive controls. To determine whether hypertension impairs thermoregulatory reflex cutaneous vasodilation we observed the tail skin vasodilator responses to body heating in male SHR and normotensive Wistar-Kyoto rats (WKY) anesthetized with chloralose and urethan (80 mg/kg and 500 mg/kg ip, respectively). A pulsed-Doppler flow probe was placed on the caudal artery at its origin to monitor tail blood flow (TBF) velocity (the tail skin is the major thermoregulatory organ of the rat), and a catheter was placed in a femoral artery to monitor arterial pressure and heart rate. Internal temperature was measured via a thermistor placed approximately 10 cm down the esophagus into the gastrointestinal tract. During normothermia, TBF was not different between SHR and WKY (0.10 +/- 0.01 vs. 0.15 +/- 0.02 kHz; P > 0.05), whereas tail vascular conductance (TVC) was significantly lower in SHR vs. WKY (0.73 +/- 0.14 vs. 1.88 +/- 0.31 Hz/mmHg; P < 0.05). In response to body heating (tail remained exposed to room temperature), the increases in TBF and TVC were markedly less SHR than in WKY (0.73 +/- 0.14 kHz and 6.03 +/- 1.11 Hz/mmHg vs. 2.61 +/- 0.35 kHz and 22.48 +/- 2.69 Hz/mmHg, respectively). After lumbar sympathectomy, TBF and TVC were not different from the values observed during hyperthermia in both groups. This indicates that the impaired cutaneous vasodilation observed in SHR was not due to failure to withdraw sympathetic vasoconstrictor tone. We conclude that thermoregulatory reflex vasodilation of the cutaneous vasculature is markedly impaired in SHR.
Authors:
D S O'Leary; G Wang
Related Documents :
8856266 - Sex chromosomes do not influence renal injury in borderline hypertensive rats.
4050486 - Effects of ageing on cardiac performance and coronary flow in spontaneously hypertensiv...
2641416 - Pressor responsiveness to vasopressin in spontaneously hypertensive rats.
1849526 - Protective effects of antihypertensive treatment with isradipine on the consequences of...
2927036 - Relation of intrinsic heart rate and autonomic nervous tone to resting heart rate in th...
22474806 - Catecholamine-resistant hypotension following induction for spinal exploration.
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.    
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  77     ISSN:  8750-7587     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  1994 Aug 
Date Detail:
Created Date:  1995-01-20     Completed Date:  1995-01-20     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  692-6     Citation Subset:  IM    
Affiliation:
Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan 48201.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure
Body Temperature Regulation*
Heart Rate
Hypertension / genetics,  physiopathology*
Male
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Skin / blood supply*
Sympathectomy
Tail / blood supply
Vascular Resistance
Vasodilation*
Grant Support
ID/Acronym/Agency:
HL-02844/HL/NHLBI NIH HHS

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  Higher exercise performance and lower VO2max in Tibetan than Han residents at 4,700 m altitude.
Next Document:  Roles of intra- and extracellular carbonic anhydrase in alveolar-capillary CO2 equilibration.