Linked Life Data

17120018

Source:http://linkedlifedata.com/resource/pubmed/id/17120018

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2007-3-5
pubmed:abstractText
Acute hypoxia increases ventilatory drive in conscious animals, resulting in tachycardia. Sustained hypoxia changes the initial chemoreflex ventilatory increase to secondary ventilatory depression, which then evokes a gradual secondary heart rate (HR) reduction. Prostacyclin (PGI(2)) release is known to potentiate alpha(2)-adrenoreceptor (alpha(2)-AR) mediated inhibition of sympathoactivation during ischaemia and hypoxia. We examined whether alpha(2)-AR mediated sympathoinhibition was responsible for limiting hypoxic heart rate increases during initial sympathoactivation, and subsequent secondary HR depression, and if PGI(2) is required for sympathoinhibition of HR. The responses of unrestrained PGI(2) synthase deficient (PGID) and wild type (WT) mice to acute hypoxia (10% O(2) for 30 min) were investigated by simultaneous telemetry, whole body plethysmography and open-flow respirometry. PGID mice exhibited potentiated .V(E) (p < 0.007) after intraperitoneal vehicle injection (n = 8), but not so HR responses compared to WT mice during sustained hypoxia. Idazoxan (alpha(2)-AR antagonist, i.p. bolus 3 mg/kg) pretreatment did not change hypoxic ventilatory response in either group, but significantly elevated hypoxic HR in WT mice only (p < 0.013). Sodium meclofenamate (cyclooxygenase inhibition, i.p. bolus 25 mg/kg) pretreatment eliminated the potentiated .V(E) of PGID and caused significant basal hypotension that led to a transient hypertensive response to hypoxia. From these results, we suggest that alpha(2)-AR activation is required for coupling HR to central inspiratory drive during acute hypoxia, and that PGI(2) is required to enhance the inhibition of sympathoactivation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
454
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
29-39
pubmed:meshHeading
pubmed-meshheading:17120018-Acute Disease, pubmed-meshheading:17120018-Adrenergic alpha-Antagonists, pubmed-meshheading:17120018-Animals, pubmed-meshheading:17120018-Anoxia, pubmed-meshheading:17120018-Blood Pressure, pubmed-meshheading:17120018-Cyclooxygenase Inhibitors, pubmed-meshheading:17120018-Cytochrome P-450 Enzyme System, pubmed-meshheading:17120018-Heart Rate, pubmed-meshheading:17120018-Hypertension, pubmed-meshheading:17120018-Hypotension, pubmed-meshheading:17120018-Idazoxan, pubmed-meshheading:17120018-Intramolecular Oxidoreductases, pubmed-meshheading:17120018-Male, pubmed-meshheading:17120018-Meclofenamic Acid, pubmed-meshheading:17120018-Mice, pubmed-meshheading:17120018-Mice, Inbred C57BL, pubmed-meshheading:17120018-Mice, Knockout, pubmed-meshheading:17120018-Neural Inhibition, pubmed-meshheading:17120018-Receptors, Adrenergic, alpha-2, pubmed-meshheading:17120018-Respiration, pubmed-meshheading:17120018-Sympathetic Nervous System
pubmed:year
2007
pubmed:articleTitle
Alpha2-adrenoreceptor mediated sympathoinhibition of heart rate during acute hypoxia is diminished in conscious prostacyclin synthase deficient mice.
pubmed:affiliation
Department of Cardiac Physiology, National Cardiovascular Center Research Institute, Suita-shi, Osaka 565-8565, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't