Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1991-8-1
pubmed:abstractText
Brain extracellular potassium [( K+]ec) in the ventral respiratory group of the medulla and the phrenic neurogram were recorded in anesthetized vagotomized peripherally chemodenervated ventilated cats during progressive isocapnic carbon monoxide (CO) hypoxia. During hypoxia, the phrenic neurogram was progressively depressed and became silent when arterial O2 content (CaO2) was reduced by 62 +/- 3% (SE). Gasping was seen in the phrenic neurogram when CaO2 was reduced by 78 +/- 1%. Medullary [K+]ec, an indicator of energy production failure due to O2 insufficiency, was 3.2 +/- 0.4 mM before hypoxia and was statistically unchanged at the onset of phrenic apnea during CO hypoxia (4 +/- 0.7 mM). By the onset of gasping, [K+]ec had increased to 6.1 +/- 1 mM, a value that tended to be different from control (P less than 0.1). After initiation of gasping, the rate of rise of [K+]ec increased, and [K+]ec reached a maximum value of 14.3 +/- 2.7 mM before hypoxia was terminated. With reoxygenation, [K+]ec returned to control levels within 20 min. On the basis of these results, we have drawn two major conclusions. 1) Hypoxic depression to the point of phrenic apnea does not appear to be caused by medullary energy insufficiency as measured by loss of [K+]ec homeostasis. 2) The rapid rise in [K+]ec in the medulla that characterizes severe hypoxia is closely associated with the onset of gasping in the phrenic neurogram, suggesting that gasping may serve as a marker for loss of medullary ionic homeostasis and thus onset of medullary energy insufficiency during hypoxia.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
70
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1477-82
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Extracellular potassium homeostasis in the cat medulla during progressive brain hypoxia.
pubmed:affiliation
Department of Medicine, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick 08903-0019.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.