title: Uncoupling protein expression in skeletal muscle and adipose tissue in response to in vivo porcine somatotropin treatment.
abstract: These experiments examined the potential roles of somatropin (pST) and IGF-I in the regulation of uncoupling protein (UCP)2 and UCP3 and their regulatory proteins peroxisome proliferator activated receptor (PPAR) alpha, gamma and delta using in vivo pST treatment of swine and in vitro supplementation of pST or IGF-I to adipose slices. Six, 90kg barrows were treated with recombinant pST (10mg) for 2 week while another six pigs were injected with buffer. Total RNA from outer subcutaneous adipose (OSQ) and middle subcutaneous adipose (MSQ) tissues, leaf fat, liver and longissimus (LM) was amplified by reverse transcription-PCR with quantification of transcripts by capillary electrophoresis with laser-induced fluorescence detection. UCP2 mRNA abundance increased in liver (P<0.001) and all three adipose tissues by pST treatment (P<0.05). Administration of pST increased UCP3 mRNA abundance by 42% in LM (P<0.01). PPARalpha mRNA abundance increased with pST treatment by 29% in liver (P<0.05), while decreasing 25% in LM (P<0.05). PPARgamma mRNA abundance decreased 32% (P<0.01) while PPARdelta increased 48% in LM (P<0.01) with pST administration. In vitro, pST reduced UCP2 mRNA abundance in OSQ and MSQ tissue slices (P<0.05). UCP3 mRNA abundance decreased in OSQ (P<0.05) but increased in MSQ (P<0.05) with pST. In contrast, IGF-I increased UCP2 and UCP3 mRNA abundance in both MSQ and OSQ slices (P<0.05). These experiments suggest pST, IGF-I and metabolic adaptations to pST contribute to regulating UCP2 and UCP3.
authors.affiliation: Growth Biology Laboratory, U.S. Department of Agriculture-Agricultural Research Service, Beltsville, MD 20705, USA. timothy.ramsay@ars.usda.gov
authors.forename: T G
authors.initials: TG
authors.lastname: Ramsay
authors.forename: A D
authors.initials: AD
authors.lastname: Mitchell
authors.forename: M P
authors.initials: MP
authors.lastname: Richards
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D019075:Electrophoresis, Capillary / Q000662:veterinary; D005786:Gene Expression Regulation / Q000502:physiology; D013006:Growth Hormone / Q000494:pharmacology*; D006854:Hydrocortisone / Q000097:blood; D007328:Insulin / Q000097:blood / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism / Q000494:pharmacology; D007473:Ion Channels / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D024101:Mitochondrial Proteins / Q000096:biosynthesis* / Q000235:genetics; D018482:Muscle, Skeletal / Q000187:drug effects / Q000378:metabolism*; D047492:Peroxisome Proliferator-Activated Receptors / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D050151:Subcutaneous Fat / Q000187:drug effects / Q000378:metabolism*; D013552:Swine / Q000378:metabolism*; D014284:Triiodothyronine / Q000097:blood; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3
chemical_list: D001786:Blood Glucose; D007328:Insulin; D007473:Ion Channels; D024101:Mitochondrial Proteins; D047492:Peroxisome Proliferator-Activated Receptors; D012333:RNA, Messenger; D000071246:Uncoupling Protein 2; D000071247:Uncoupling Protein 3; D014284:Triiodothyronine; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D006854:Hydrocortisone