Vascularization of the Arteriovenous Loop in a Rat Isolation Chamber Model-Quantification of Hypoxia and Evaluation of Its Effects.

Abstract

INTRODUCTION:

The aim of this study was to analyze the three-dimensional distribution of hypoxia in the arteriovenous (AV) loop model in rats, by examining the distribution of hypoxia-inducible factor-1 alpha (HIF-1α).

MATERIALS AND METHODS:

AV loops were created from the femoral artery and vein of male Lewis rats and an interpositional graft from the contralateral femoral vein. This AV fistula was embedded in a fibrin-filled isolation chamber and subcutaneously implanted into the thigh. The specimens were harvested after 7 days (n = 4), 10 days (n = 5), and 14 days (n = 4). The fibrin clots were stained for lectin, HIF-1α, and ectodysplasin 1 (ED1). The distribution of positive and negative cells was analyzed in three dimensions and at different points in time.

RESULTS:

The HIF-1α-positive rate increased from the proximity of the central vessel to the distant regions. From day 7 to 10, we noted a decrease in the HIF-1α-positive rate in the proximity of the vessels and an increase in the periphery. A global decrease in positive cells was seen at day 14. HIF-1α and macrophage (ED1) double staining indicated that macrophages accounted for a significant fraction of the cells. Double staining for endothelium (with lectin) demonstrated that no HIF-1α was detectable in well-vascularized areas.

CONCLUSION:

In the AV loop model, the HIF-1α-positive cell distribution is highly related to the vascularization process. The onset of rapid vessel outgrowth follows the increase of the HIF-1α rate closely, indicating that HIF-1α may be a driving force for vascularization.

• Authors: Quan Yuan, Andreas Arkudas, Raymund E Horch, Matthias Hammon, Oliver Bleiziffer, Michael Uder, Hannes Seuss
• Journal: Tissue engineering. Part A (Tissue Eng Part A) Vol. 24 Issue 9-10 Pg. 719-728 (05 2018) ISSN: 1937-335X [Electronic] United States
• PMID: 28978278 (Publication Type: Journal Article)

Chemical References

• Hypoxia-Inducible Factor 1, alpha Subunit
• Fibrin

Topics

• Animals
• Fibrin (chemistry)
• Hypoxia (metabolism, pathology)
• Hypoxia-Inducible Factor 1, alpha Subunit (metabolism)
• Male
• Neovascularization, Pathologic (metabolism, pathology)
• Rats
• Rats, Inbred Lew
• Tissue Engineering (methods)