title: Acute cold- and chronic heat-exposure upregulate hepatic leptin and muscle uncoupling protein (UCP) gene expression in broiler chickens.
abstract: Emerging evidence showed that variations in environmental temperature affect both leptin and uncoupling protein (UCP) gene expression in mammals, whereas a little is known about such interactions in birds. Thus, we conducted the present study to investigate the influence of acute (2 hours) cold (4 degrees C) and chronic (10 days) heat (32 degrees C) exposure on hepatic leptin and muscle UCP gene expression in 5-wk-old broiler chickens. Both cold- and heat-exposure significantly (P < 0.05 to P < 0.001) upregulated hepatic leptin (by 35 and 46%, respectively) and muscle UCP mRNA levels (by 71 and 71%, respectively) compared to the thermoneutrality (22 degrees C). This result suggests that leptin and UCP may be involved in the thermoregulation response of chickens to extreme climate (cold and hot temperatures). The upregulation of hepatic leptin gene expression was accompanied by an increase in plasma leptin levels, indicating that leptin may be regulated at transcriptional level. The increase of leptin and UCP mRNA abundance, and leptinemia we report here were not related to plasma glucose or insulin levels. In conclusion, the exposure of broiler chickens to extreme ambient temperatures (cold and heat) increases hepatic leptin and muscle UCP gene expression.
authors.affiliation: INRA, UR83 RecherchesAvicoles, Nouzilly, France. sami.dridi@uky.edu
authors.forename: Sami
authors.initials: S
authors.lastname: Dridi
authors.forename: Soraya
authors.initials: S
authors.lastname: Temim
authors.forename: Michel
authors.initials: M
authors.lastname: Derouet
authors.forename: Sophie
authors.initials: S
authors.lastname: Tesseraud
authors.forename: Mohammed
authors.initials: M
authors.lastname: Taouis
mesh_terms: D000818:Animals; D030161:Avian Proteins / Q000235:genetics / Q000378:metabolism*; D001786:Blood Glucose / Q000378:metabolism; D001823:Body Composition / Q000502:physiology; D001833:Body Temperature Regulation / Q000502:physiology; D002645:Chickens / Q000378:metabolism*; D003080:Cold Temperature; D004734:Energy Metabolism / Q000502:physiology; D005786:Gene Expression Regulation; D006358:Hot Temperature; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000235:genetics / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D000071245:Mitochondrial Uncoupling Proteins; D018482:Muscle, Skeletal / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D015854:Up-Regulation / Q000502:physiology
chemical_list: D030161:Avian Proteins; D001786:Blood Glucose; D007328:Insulin; D020738:Leptin; D024101:Mitochondrial Proteins; D000071245:Mitochondrial Uncoupling Proteins; D012333:RNA, Messenger; C422907:mitochondrial uncoupling protein, chicken