Prolactin and growth hormone regulate adiponectin secretion and receptor expression in adipose tissue.
Adiponectin is a hormone secreted from adipose tissue, and serum levels are decreased with obesity and insulin resistance. Because prolactin (PRL) and growth hormone (GH) can affect insulin sensitivity, we investigated the effects of these hormones on the regulation of adiponectin in human adipose tissue in vitro and in rodents in vivo. Adiponectin secretion was significantly suppressed by PRL and GH in in vitro cultured human adipose tissue. Furthermore, PRL increased adiponectin receptor 1 (AdipoR1) mRNA expression and GH decreased AdipoR2 expression in the cultured human adipose tissue. In transgenic mice expressing GH, and female mice expressing PRL, serum levels of adiponectin were decreased. In contrast, GH receptor deficient mice had elevated adiponectin levels, while PRL receptor deficient mice were unaffected. In conclusion, we demonstrate gene expression of AdipoR1 and AdipoR2 in human adipose tissue for the first time, and show that these are differentially regulated by PRL and GH. Both PRL and GH reduced adiponectin secretion in human adipose tissue in vitro and in mice in vivo. Decreased serum adiponectin levels have been associated with insulin resistance, and our data in human tissue and in transgenic mice suggest a role for adiponectin in PRL and GH induced insulin resistance.
Nilsson
Louise
L
Department of Physiology, Göteborg University, 405 30 Göteborg, Sweden. louise.nilsson@fysiologi.gu.se
Binart
Nadine
N
Bohlooly-Y
Mohammad
M
Bramnert
Margareta
M
Egecioglu
Emil
E
Kindblom
Jon
J
Kelly
Paul A
PA
Kopchick
John J
JJ
Ormandy
Christopher J
CJ
Ling
Charlotte
C
Billig
Håkan
H
D000328:Adult; D000818:Animals; D005260:Female; D013006:Growth Hormone / Q000502:physiology*; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008875:Middle Aged; D011388:Prolactin / Q000502:physiology*; D054419:Receptors, Adiponectin; D011956:Receptors, Cell Surface / Q000235:genetics* / Q000378:metabolism; D011981:Receptors, Prolactin / Q000235:genetics / Q000378:metabolism*
C475418:ADIPOR1 protein, human; C475420:ADIPOR2 protein, human; D054419:Receptors, Adiponectin; D011956:Receptors, Cell Surface; D011981:Receptors, Prolactin; D011388:Prolactin; D013006:Growth Hormone