The role of androgens on hypoxia-inducible factor (HIF)-1α-induced angiogenesis and on the survival of ischemically challenged skin flaps in a rat model

Microsurgery. 2012 Sep;32(6):475-81. doi: 10.1002/micr.21996. Epub 2012 Jun 18.

Abstract

Background: Effects of androgens on angiogenesis are controversial. Hypoxia-inducible factor (HIF)-1α promotes expression of vascular endothelial growth factor (VEGF) that stimulates angiogenesis.

Purpose: This study investigates whether androgens stabilize HIF-1α in endothelial cells, and androgen depletion decreases VEGF concentrations and skin flap survival.

Materials and methods: Male human umbilical vein endothelial cells (HUVECs) were exposed to dihydrotestosterone (DHT) and HIF-1α expression was measured. In male Wistar rats, standardized proximally based random pattern dorsal skin flaps (3 × 9 cm) were raised 4 weeks after orchiectomy and sham operation, respectively (n = 10, each). Flap VEGF concentrations (immunohistochemistry), perfusion (Laser Doppler), and viability (digital planimetry) were measured.

Results: DHT induced HIF-1α expression in HUVECs. Androgen depletion induced decreased VEGF expression (P = 0.003), flap perfusion (P < 0.05), and survival (44.4% ± 5.2%) compared to controls (35.5% ± 4.5%; P = 0.003).

Conclusion: In vitro, androgens may stimulate HIF-1α under normoxic conditions. In rats, androgen depletion decrease VEGF expression and flap survival.

MeSH terms

  • Androgens / physiology*
  • Animals
  • Biomarkers / metabolism
  • Blotting, Western
  • Cells, Cultured
  • Dihydrotestosterone*
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Immunohistochemistry
  • Ischemia*
  • Laser-Doppler Flowmetry
  • Male
  • Neovascularization, Physiologic / physiology*
  • Orchiectomy
  • Rats
  • Rats, Wistar
  • Surgical Flaps / blood supply*
  • Surgical Flaps / physiology
  • Vascular Endothelial Growth Factor A / metabolism*
  • Wound Healing / physiology

Substances

  • Androgens
  • Biomarkers
  • HIF1A protein, human
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Vascular Endothelial Growth Factor A
  • vascular endothelial growth factor A, rat
  • Dihydrotestosterone