Related Experiment Videos
Evidence of specificity in the action of angiogenesis antagonists
1Department of Pathology, University of Göteborg, Sahlgrenska University Hospital, Sweden.
Abstract:
It is not known whether each type of angiogenesis reaction has a specific antiangiogenic mechanism and to what extent angiostatic agents can exert additional or synergistic effects. The objective of this study was to elucidate the way in which systemic angiostatic drug treatment by either one drug at a time or two in combination affects distinct angiogenesis reactions in one and the same vascular bed. The chemically unrelated drugs which were used were dexamethasone (DE) and ciclosporin A (CS) at nontoxic doses in the range used clinically. These drugs are known to act angiostatically in the rat. The rat mesenteric window angiogenesis assay was used to assess the systemic effect of DE, CS and DE plus CS in saline-mediated angiogenesis (SMA) and mast-cell-mediated angiogenesis (MCMA). Angiogenesis was quantified by microscopic and morphometric means, one variable being the number of vessel profiles per unit tissue length (No/UL), a measure related to the degree of microvascular branching and tortuosity. Whereas CS significantly suppressed No/UL in SMA without substantially affecting MCMA, DE plus CS significantly suppressed No/UL in MCMA, but, unexpectedly, somewhat increased No/UL in SMA. As compared with either drug given alone, the coadministration of the drugs clearly did not enhance the antiangiogenic effect in SMA. The drugs, whether alone or in combination specifically and selectively suppressed the angiogenesis reactions which were examined, thereby suggesting distinct antiangiogenic mechanisms in SMA and MCMA.
Insights
Angiogenesis reactions show distinct responses to anti-angiogenic drugs. Dexamethasone and cyclosporin A selectively suppressed specific angiogenesis types, suggesting unique anti-angiogenic mechanisms.
Area of Science:
- Vascular biology
- Pharmacology
- Biomedical research
Background:
- Angiogenesis, the formation of new blood vessels, is crucial for various physiological and pathological processes.
- The specific anti-angiogenic mechanisms for different types of angiogenesis reactions remain largely unknown.
- Understanding these mechanisms is vital for developing targeted therapies.
Purpose of the Study:
- To investigate the effects of systemic angiostatic drug treatment on distinct angiogenesis reactions.
- To determine if anti-angiogenic drugs, alone or in combination, exhibit specific or synergistic effects.
- To elucidate the anti-angiogenic mechanisms in saline-mediated angiogenesis (SMA) and mast-cell-mediated angiogenesis (MCMA).
Main Methods:
- Utilized the rat mesenteric window angiogenesis assay to assess systemic drug effects.
- Administered dexamethasone (DE) and ciclosporin A (CS) at non-toxic, clinically relevant doses.
- Quantified angiogenesis by measuring the number of vessel profiles per unit tissue length (No/UL) using microscopic and morphometric analysis.
Main Results:
- Ciclosporin A (CS) significantly suppressed No/UL in SMA but minimally affected MCMA.
- Dexamethasone (DE) plus CS significantly suppressed No/UL in MCMA, unexpectedly increasing it in SMA.
- Combined DE and CS did not enhance the anti-angiogenic effect in SMA compared to individual drug administration.
Conclusions:
- DE and CS selectively suppressed distinct angiogenesis reactions, indicating specific anti-angiogenic mechanisms.
- The study suggests that different angiogenesis reactions possess unique sensitivities to angiostatic agents.
- Findings imply that tailored drug combinations may be necessary for effective anti-angiogenic therapy.