Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3 Pt 2
pubmed:dateCreated
1990-4-23
pubmed:abstractText
Regulation of glycolysis was assessed in winter- and summer-acclimatized goldfinches (Carduelis tristis). We exposed birds to a thermo-neutral temperature (30 degrees C), moderate cold (-15 degrees C), and severe cold (0 degrees C in an atmosphere of 21% O2-79% He), and then measured concentrations of glycogen, glycolytic intermediates, and citrate in the pectoralis muscles. Winter birds used less glycogen when exposed to moderate cold than did summer birds, confirming the carbohydrate sparing noted by Marsh and Dawson [Am. J. Physiol. 242 (Regulatory Integrative Comp. Physiol. 11): R563-R569, 1982]. However, depletion of muscle glycogen did not correlate with thermoregulatory failure in this study. Concentrations of glucose 6-phosphate and fructose 6-phosphate in the pectoralis muscles were approximately 1.9 and 0.3 mumol/g wet mass in birds exposed to thermoneutral temperatures. The levels of these intermediates fell 50-70% under conditions known to enhance flux through glycolysis as indicated by increased glucose turnover and glycogen depletion. This information identifies phosphofructokinase (PFK) as a major regulated step in glycolysis in these highly aerobic skeletal muscles. Winter birds maintained the inhibition of this step under conditions of moderate cold. However, concentrations of citrate, which have been hypothesized to be an important inhibitor of PFK, did not correlate with the observed pattern of inhibition. Therefore, if the enhanced beta-oxidative capacity of winter birds is important in the regulation of glycolysis, a mechanism other than the accumulation of citrate may be involved.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
258
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
R711-7
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Regulation of glycolysis in the pectoralis muscles of seasonally acclimatized American goldfinches exposed to cold.
pubmed:affiliation
Department of Biology, Northeastern University, Boston, Massachusetts 02115.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.