Chick subcutaneous and abdominal adipose tissue depots respond differently in lipolytic and adipogenic activity to α-melanocyte stimulating hormone (α-MSH)

Comp Biochem Physiol A Mol Integr Physiol. 2017 Jul:209:56-64. doi: 10.1016/j.cbpa.2017.04.013. Epub 2017 Apr 22.

Abstract

In birds, α-MSH is anorexigenic, but effects on adipose tissue are unknown. Four day-old chicks were intraperitoneally injected with 0 (vehicle), 5, 10, or 50μg of α-MSH and subcutaneous and abdominal adipose tissue collected at 60min for RNA isolation (n=10). Plasma was collected post-euthanasia at 60 and 180min for measuring non-esterified fatty acids (NEFA) and α-MSH (n=10). Relative to the vehicle, food intake was reduced in the 50μg-treated group. Plasma NEFAs were greater in 10μg than vehicle-treated chicks at 3h. Plasma α-MSH was 3.06±0.57ng/ml. In subcutaneous tissue, melanocortin receptor 5 (MC5R) mRNA was increased in 10μg, MC2R and CCAAT-enhancer-binding protein β (C/EBPβ) mRNAs increased in 50μg, peroxisome proliferator-activated receptor γ and C/EBPα decreased in 5, 10 and 50μg, and Ki67 mRNA decreased in 50μg α-MSH-injected chicks, compared to vehicle-injected chicks. In abdominal tissue, adipose triglyceride lipase mRNA was greater in 10μg α-MSH- than vehicle-treated chicks. Cells isolated from abdominal fat that were treated with 10 and 100nM α-MSH for 4h expressed more MC5R and perilipin-1 than control cells (n=6). Cells that received 100nM α-MSH expressed more fatty acid binding protein 4 and comparative gene identification-58 mRNA than control cells. Glycerol-3-phosphate dehydrogenase (G3PDH) activity was greater in cells at 9days post-differentiation that were treated with 1 and 100nM α-MSH for 4h than in control cells (n=3). Results suggest that α-MSH increases lipolysis and reduces adipogenesis in adipose tissue.

Keywords: Adipogenesis; Adipose tissue; Chick; Lipolysis; α-MSH.

MeSH terms

  • Abdominal Fat / drug effects
  • Abdominal Fat / metabolism*
  • Adipogenesis / drug effects*
  • Adipose Tissue / drug effects
  • Adipose Tissue / metabolism*
  • Animals
  • Chickens / metabolism*
  • Chickens / physiology
  • Eating
  • Lipolysis / drug effects
  • Melanocyte-Stimulating Hormones / pharmacology

Substances

  • Melanocyte-Stimulating Hormones