Linked Life Data

15743892

Source:http://linkedlifedata.com/resource/pubmed/id/15743892

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2005-6-15
pubmed:abstractText
Force characteristics of skeletal muscle of knockout mice lacking creatine (Cr) due to a deletion of guanidinoacetate methyltransferase (GAMT) were studied in situ. Medial gastrocnemius muscles of anesthetized GAMT-deficient (GAMT-/-) and control (Con) littermates were stimulated at optimum length via the sciatic nerve at different stimulation frequencies (60-250 Hz). GAMT-/- mice showed reduced maximal tetanic and twitch force, reduced relative force at 60 Hz, and increased relaxation times. High-intensity fatigue protocols consisting of 30 successive isometric or dynamic contractions showed a strong reduction in force at the beginning of the series in GAMT-/- mice, followed by a smaller reduction compared with Con littermates toward the end of the series. Cr supplementation for 2 days in GAMT-/- animals (GAMT(Cr)-/-) resulted in normalization to Con values for relaxation times, relative force at lower stimulation frequencies, and relative force during 30 isometric contractions. Force per muscle mass, however, remained decreased. Furthermore,GAMT(Cr)-/- mice showed differences compared with both Con and unsupplemented animals in maximal rates of force rise and relaxation times during the isometric protocol as well as in force during the dynamic protocol. Our results show that the absence of Cr plays a direct role in relaxation times, maximal rate of force rise, and force production during high-intensity fatigue protocols. The lower force per muscle mass, however, is probably caused by other factors; i.e., high intracellular guanidinoacetate concentrations.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0363-6143
pubmed:author
pubmed:issnType
Print
pubmed:volume
289
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C113-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Lower force and impaired performance during high-intensity electrical stimulation in skeletal muscle of GAMT-deficient knockout mice.
pubmed:affiliation
Department of Radiology (430), Radboud University Nijmegen Medical Center, Geert Grooteplein 10, PO Box 9101, 6500 HB Nijmegen, The Netherlands. h.kan@rad.umcn.nl
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't