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Updated: Aug 25, 2026
Rat Mesentery Angiogenesis Assay
Published on: June 18, 2011
Effect of human Angiostatin protein on human angiogenesis in vitro
Sung Pil Jung1, Brett Siegrist, Yi-Zarn Wang
1Department of Surgery, Louisiana State University Health Sciences Center, New Orleans, Louisiana 70112, USA.
Abstract:
Angiostatin, a 38-kD fragment of plasminogen, inhibits angiogenesis in both animal tumor models and in vitro endothelial cell models. However, human Angiostatin has not been tested in vitro against an intact human tissue target to determine its ability to inhibit the initiation or subsequent promotion of the human angiogenic response. We hypothesized that high doses of human Angiostatin would inhibit the development of an angiogenic response in an intact human vessel target, and would suppress the subsequent growth of blood vessels following the initiation of an angiogenic response. To test these hypotheses, full-thickness human placental vein disks were cultured for 15 days in an in vitro fibrin-thrombin clot assay. This assay system had been used to evaluate the efficacy of a wide variety of compounds. Vessels were obtained from three placentas. Treatments included a control medium plus fetal bovine serum (FBS), heparin-steroid (300 micro g/ml heparin and 350 micro g/ml hydrocortisone; a treatment known to inhibit angiogenesis) and Angiostatin at doses from 1 x 10(-4) to 1 x 10(-9) M. In the control groups, 81% of vessels initiated an angiogenic response compared to 53% of the vessels treated with heparin-steroid. Angiostatin (10(-4)-10(-9) M) decreased the initiation of an angiogenic response, but this was not statistically significant. Of the disks that initiated an angiogenic response, the mean ( +/- standard error of the mean (SEM)) semi-quantitative visual angiogenic index (AI) of the control vessels was 9 +/- 1.7 on day 15. In comparison, the mean AI of heparin-steroid treated vessels was 3.7 +/- 0.4. Angiostatin at doses of 10(-4)-10(-9) M also failed to inhibit blood vessel growth after initiation of the angiogenic response. Based on these observations, we cannot demonstrate significant activity of human Angiostatin (10(-4)-10(-9) M) against the initiation or promotion of a human angiogenic response in this in vitro model of angiogenesis using an intact human vessel target.
Insights
Human Angiostatin did not significantly inhibit angiogenesis in an intact human vessel model. This study found no evidence that Angiostatin prevents blood vessel growth initiation or promotion in vitro.
Area of Science:
- Biomedical research
- Vascular biology
- Angiogenesis research
Background:
- Angiostatin, a plasminogen fragment, shows anti-angiogenic properties in animal and cell models.
- Human Angiostatin's efficacy on intact human vessels in vitro remains unverified.
- Angiogenesis is crucial for tumor growth and other pathological processes.
Purpose of the Study:
- To evaluate human Angiostatin's ability to inhibit angiogenesis in an intact human vessel model.
- To determine if Angiostatin affects the initiation and subsequent promotion of human angiogenic responses.
- To test high doses of human Angiostatin in a validated in vitro assay.
Main Methods:
- Utilized full-thickness human placental vein disks cultured in a fibrin-thrombin clot assay for 15 days.
- Tested treatments including control medium with FBS, a known angiogenesis inhibitor (heparin-steroid), and human Angiostatin (10⁻⁴–10⁻⁹ M).
- Assessed the initiation and visual angiogenic index (AI) of blood vessel growth.
Main Results:
- Control vessels showed an 81% angiogenic response rate; heparin-steroid treated vessels showed 53%.
- Angiostatin (10⁻⁴–10⁻⁹ M) did not significantly inhibit the initiation of angiogenesis.
- Angiostatin failed to suppress blood vessel growth after angiogenesis was initiated, unlike the heparin-steroid control.
Conclusions:
- Human Angiostatin (10⁻⁴–10⁻⁹ M) demonstrated no significant anti-angiogenic activity in this in vitro model using intact human vessels.
- The study could not confirm Angiostatin's efficacy against the initiation or promotion of human angiogenesis.
- Further research may be needed to explore Angiostatin's potential in different contexts or concentrations.
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