Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1994-3-2
pubmed:abstractText
Sixty crossbred barrows were used to study the effect of ractopamine (a phenethanolamine/beta-adrenergic agonist) treatment and its withdrawal on muscle growth and on the relative abundance of skeletal muscle alpha-actin (sk-alpha-actin) mRNA and of liver and longissimus muscle IGF-I mRNA at 4 wk. Ractopamine was fed (20 ppm) for periods of 2, 4, and 6 wk (six pigs per group). Additional pigs (four per group) were fed ractopamine (20 ppm) for 6 wk and then slaughtered 1, 3, and 7 d after withdrawal of ractopamine. Ractopamine increased (P < .05) longisimus muscle weight and protein content, although protein concentrations were not different. The increased muscle weight and protein content attained by feeding ractopamine for 6 wk was retained when ractopamine was withdrawn. The RNA and DNA concentrations did not change, whereas total DNA and RNA content per muscle was 18 and 26.7% greater, respectively, in ractopamine-treated pigs at 4 wk, but there were no differences at 2 or 6 wk or among the withdrawal groups. The relative abundance of sk-alpha-actin mRNA in the longissimus muscle was 41 and 62% greater (P < .05) in treated animals at 2 and 4 wk but was similar to that in controls at 6 wk and during the withdrawal period. The relative abundance of IGF-I mRNA in liver and longissimus muscle was not altered with ractopamine treatment for 4 wk. These results indicate that the ractopamine-enhanced muscle growth may result from increased myofibrillar gene expression at the pretranslational level, which is maximal with short-term treatment of ractopamine.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-8812
pubmed:author
pubmed:issnType
Print
pubmed:volume
71
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3319-26
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Skeletal muscle growth and expression of skeletal muscle alpha-actin mRNA and insulin-like growth factor I mRNA in pigs during feeding and withdrawal of ractopamine.
pubmed:affiliation
Department of Animal Science, Michigan State University, East Lansing 48824.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't