Stimulation of lipolysis but not of leptin release by growth hormone is abolished in adipose tissue from Stat5a and b knockout mice.
The present studies examined the effects of growth hormone (GH) on lipolysis and leptin release by adipose tissue from mice incubated for 24 h in primary culture. In adipose tissue from control mice GH enhanced lipolysis without affecting leptin release. The lipolytic action of GH was unaffected in adipose tissue from Stat5b-/- male mice but leptin release was enhanced by GH in fat from Stat5b-/- mice. In adipose tissue from Stat5ab-/- female mice no significant lipolytic action of GH was seen but leptin release was enhanced by GH. An insulin-like effect of GH on glucose conversion to lactate was also seen in mice deficient in Stat5ab-/-. These results suggest that the lipolytic action of GH involves the Stat5 proteins while the insulin-like effects of GH on glucose metabolism and leptin release involve different mechanisms.
Fain
J N
JN
Department of Biochemistry, College of Medicine, University of Tennessee, Memphis, Tennessee 38163, USA. jfain@utmem.edu
Ihle
J H
JH
Bahouth
S W
SW
D000273:Adipose Tissue / Q000187:drug effects* / Q000502:physiology*; D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D005260:Female; D005947:Glucose / Q000378:metabolism; D019382:Human Growth Hormone / Q000494:pharmacology*; D006801:Humans; D020738:Leptin; D008066:Lipolysis / Q000187:drug effects*; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D008894:Milk Proteins; D011506:Proteins / Q000378:metabolism*; D011965:Receptors, Glucocorticoid / Q000502:physiology; D050799:STAT5 Transcription Factor; D015398:Signal Transduction; D015534:Trans-Activators / Q000235:genetics / Q000502:physiology*; D025521:Tumor Suppressor Proteins
D004268:DNA-Binding Proteins; D020738:Leptin; D008894:Milk Proteins; D011506:Proteins; D011965:Receptors, Glucocorticoid; D050799:STAT5 Transcription Factor; C494092:STAT5A protein, human; C494095:STAT5B protein, human; C494093:Stat5a protein, mouse; C494096:Stat5b protein, mouse; D015534:Trans-Activators; D025521:Tumor Suppressor Proteins; D019382:Human Growth Hormone; D005947:Glucose