Document Detail


Role of the hypothalamic PVN in the reflex reduction in mesenteric blood flow elicited by hyperthermia.
MedLine Citation:
PMID:  18945952     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The hypothalamic paraventricular nucleus (PVN) is an important integrative center in the brain. In the present study, we investigated whether the PVN is a key region in the mesenteric vasoconstriction that normally accompanies an increase in core body temperature. Anesthetized rats were monitored for blood pressure, heart rate, mesenteric blood flow, and vascular conductance. In control rats, elevation of core body temperature to 41 degrees C had no significant effect on blood pressure, increased heart rate, and reduced mesenteric blood flow by 21%. In a separate group of rats, muscimol was microinjected bilaterally (1 nmol/side) into the PVN. Compared with the control group, there was no significant difference in the blood pressure and heart rate responses elicited by the increase in core body temperature. In contrast to control animals, however, mesenteric blood flow did not fall in the muscimol-treated rats in response to the elevation in core body temperature. In a separate group, in which muscimol was microinjected into regions outside the PVN, elevating core body temperature elicited the normal reduction in mesenteric blood flow. The results suggest that the PVN may play a key role in the reflex decrease in mesenteric blood flow elicited by hyperthermia.
Authors:
Feng Chen; Melissa Dworak; Yuliang Wang; Joo Lee Cham; Emilio Badoer
Publication Detail:
Type:  Journal Article     Date:  2008-10-22
Journal Detail:
Title:  American journal of physiology. Regulatory, integrative and comparative physiology     Volume:  295     ISSN:  0363-6119     ISO Abbreviation:  Am. J. Physiol. Regul. Integr. Comp. Physiol.     Publication Date:  2008 Dec 
Date Detail:
Created Date:  2008-12-10     Completed Date:  2009-01-22     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901230     Medline TA:  Am J Physiol Regul Integr Comp Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  R1874-81     Citation Subset:  IM    
Affiliation:
School of Medical Sciences, RMIT University, PO Box 71, Bundoora 3083, Melbourne, VIC, Australia.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure
Body Temperature
Disease Models, Animal
Down-Regulation
Fever / physiopathology*
GABA Agonists / administration & dosage
Heart Rate
Male
Microinjections
Muscimol / administration & dosage
Paraventricular Hypothalamic Nucleus / drug effects,  physiopathology*
Rats
Rats, Sprague-Dawley
Receptors, GABA-A / agonists
Reflex* / drug effects
Regional Blood Flow
Splanchnic Circulation* / drug effects
Time Factors
Vasoconstriction* / drug effects
Chemical
Reg. No./Substance:
0/GABA Agonists; 0/Receptors, GABA-A; 2763-96-4/Muscimol

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


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