Growth hormone rapidly induces resistin gene expression in white adipose tissue of spontaneous dwarf (SDR) rats.
Growth hormone is an important regulator of metabolism; both acromegaly and GH therapy in GH-deficiency are associated with a tendency towards insulin-resistance and loss of adiposity. A possible mediator of these effects is the recently identified white adipose tissue (WAT)-derived factor resistin that has been shown to impair glucose tolerance and inhibit adipocyte differentiation. We found that WAT resistin gene expression was significantly suppressed in GH-deficient (SDR) rats compared with their Sprague-Dawley background strain. However, within 4 h of treatment of SDRs with a bolus of rhGH (1.5 mg/kg) there was a significant 150-170% increase in WAT resistin mRNA. Moreover, 24 h continuous infusion of recombinant human GH (1 mg/kg/day) caused marked increases in epididymal and subcutaneous WAT resistin of 720% and 950%, respectively, compared to controls. By 48 h of infusion these values had fallen to 510% and 330%. Infusion of porcine GH (1 mg/kg/day) had a similar inductive effect on WAT resistin mRNA. Our data demonstrate an unexpected marked, rapid and sustained up-regulation of resistin by GH. This may indicate a role for resistin in GH-dependent metabolic and differentiative effects in WAT.
Delhanty
Patric J D
PJ
Kolling Institute of Medical Research, Royal North Shore Hospital, University of Sydney, St Leonards, NSW, Australia. delhanty@med.usyd.edu.au
Mesotten
Dieter
D
McDougall
Fiona
F
Baxter
Robert C
RC
D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D004822:Epididymis / Q000187:drug effects / Q000378:metabolism; D013006:Growth Hormone / Q000494:pharmacology*; D006729:Hormones, Ectopic / Q000096:biosynthesis* / Q000235:genetics*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D008297:Male; D020932:Nerve Growth Factor; D011506:Proteins; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D052243:Resistin; D013552:Swine; D015854:Up-Regulation / Q000187:drug effects
D006729:Hormones, Ectopic; D036341:Intercellular Signaling Peptides and Proteins; D011506:Proteins; C499624:RETN protein, human; C486574:RETNLB protein, human; D012333:RNA, Messenger; D052243:Resistin; C499622:Retn protein, rat; C486575:Retnla protein, rat; D013006:Growth Hormone; D020932:Nerve Growth Factor