Linked Life Data

9889307

Source:http://linkedlifedata.com/resource/pubmed/id/9889307

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1999-3-12
pubmed:abstractText
We tested the hypothesis that the post-hypoxia frequency decline of phrenic nerve activity following brief, isocapnic hypoxic episodes in rats is diminished by prior hypoxic episodes and alpha2-adrenoreceptor antagonism. Anesthetized (urethane), artificially ventilated (FIO2=0.50) and vagotomized rats were presented with two or three, 5 min episodes of isocapnic hypoxia (FIO2 approximately 0.11), separated by 30 min of control, hyperoxic conditions. Phrenic nerve discharge, end-tidal CO2, and arterial blood gases were measured before during and after hypoxia. The average maximum frequency decline, measured 5 min after the first hypoxic episode, was 26+/-7 bursts/min below pre-hypoxic baseline values (a 70+/-16% decrease). By 30 min post-hypoxia, frequency had returned to baseline. Two groups of rats were then administered either: (1) saline (sham) or (2) the alpha2-receptor antagonist, RX821002 HCl (2-[2-(2-Methoxy-1,4-benzodioxanyl)] imidazoline hydrochloride; 0.25 mg/kg, i.v.). Isocapnic hypoxia was repeated 10 min later. In sham rats, the post-hypoxia frequency decline (PHFD) was significantly attenuated relative to the initial (control) response. However, PHFD was attenuated significantly more in RX821002-treated vs. sham rats (-3+/-3 bursts/min vs. -12+/-4 bursts/min @ 5 min post hypoxia for RX821002 and sham-treated, respectively; p<0.05). We conclude that the magnitude of PHFD is dependent on the prior history of hypoxia and that alpha2 adrenoreceptor activation plays a role in its underlying mechanism.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-8993
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Elsevier Science B.V.
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
817
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
25-33
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Post-hypoxia frequency decline in rats: sensitivity to repeated hypoxia and alpha2-adrenoreceptor antagonism.
pubmed:affiliation
Department of Comparative Biosciences and Center for Neuroscience, School of Veterinary Medicine, University of Wisconsin, 2015 Linden Drive West, Madison, WI, 53706, USA.bachk@svm.vetmed.wisc.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't