Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2002-4-19
pubmed:abstractText
Early after birth, piglets rely almost exclusively on muscular shivering thermogenesis to produce heat in the cold and this can possibly modulate skeletal muscle development. An experiment involving 10 individually housed piglets was conducted to determine the influence of cold (24-15 degrees C, D5C group) vs. thermoneutrality (34-30 degrees C, D5TN group) between birth and 5 days on myosin heavy chain (MyHC) polymorphism and metabolic characteristics of longissimus lumborum (LL) and rhomboideus (RH) muscles. Five additional piglets were sacrificed at birth. Piglets exposed to cold received 43% more artificial milk on a liveweight basis in order to achieve similar growth rates. D5C piglets produced 93% more heat and exhibited intense shivering during the whole experiment. Contractile and metabolic characteristics of muscles were determined by immunocytochemistry, electrophoresis and enzyme activities. At least eight MyHC isoforms were detected, including atypical expressions of the alpha-cardiac and extraocular isoforms. Dramatic changes in MyHC composition, myofiber cross-sectional area (CSA) and energy metabolism occurred between birth and 5 days. Cold exposure did not affect either the total number of fibers or the CSA, but it did influence muscle maturation. In particular, it increased the expression of alpha-cardiac and type I MyHC, and decreased that of fetal MyHC, confirming an acceleration in the rate of postnatal maturation. An increase in oxidative enzyme activities was observed in both muscles in the cold, whereas the activity of a glycolytic enzyme, lactate dehydrogenase, remained unchanged. Cold exposure also induced an increase in T3 plasma levels. The extent to which these changes are the result of sustained shivering or are due to the action of hormonal factors, such as thyroid hormones, are discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0142-4319
pubmed:author
pubmed:issnType
Print
pubmed:volume
22
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
439-52
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:11964069-Age Factors, pubmed-meshheading:11964069-Animals, pubmed-meshheading:11964069-Animals, Newborn, pubmed-meshheading:11964069-Body Temperature, pubmed-meshheading:11964069-Body Weight, pubmed-meshheading:11964069-Cold Temperature, pubmed-meshheading:11964069-Energy Metabolism, pubmed-meshheading:11964069-Glycolysis, pubmed-meshheading:11964069-Muscle, Skeletal, pubmed-meshheading:11964069-Muscle Development, pubmed-meshheading:11964069-Muscle Fibers, Fast-Twitch, pubmed-meshheading:11964069-Muscle Fibers, Skeletal, pubmed-meshheading:11964069-Muscle Fibers, Slow-Twitch, pubmed-meshheading:11964069-Myosin Heavy Chains, pubmed-meshheading:11964069-Protein Isoforms, pubmed-meshheading:11964069-RNA, Messenger, pubmed-meshheading:11964069-Swine, pubmed-meshheading:11964069-Thermogenesis, pubmed-meshheading:11964069-Up-Regulation
pubmed:year
2001
pubmed:articleTitle
Influence of early postnatal cold exposure on myofiber maturation in pig skeletal muscle.
pubmed:affiliation
INRA, Unité Mixte de Recherches sur le Veau et le Porc, Saint-Gilles, France. lefaucheur@st-gilles.rennes.inra.fr
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't