Measuring angiogenesis and hemodynamics in mice.

Area of Science:

• Vascular biology
• Oncology
• Biomedical imaging

Background:

• Accurate measurement of vascular parameters is crucial for understanding tumor growth and response to therapy.
• Existing methods may lack the resolution or scope to fully characterize complex vascular networks.

Purpose of the Study:

• To provide a detailed protocol for quantifying angiogenesis and hemodynamics in mouse tumor models.
• To establish standardized methods for in vivo microvessel analysis using advanced microscopy techniques.

Main Methods:

• Intravenous injection of fluorescein-isothiocyanate (FITC)-dextran to label microvasculature.
• Utilizing single-photon and multiphoton laser-scanning microscopy (MPLSM) for imaging within defined depths.
• Quantitative analysis of vascular density, length, diameter, and erythrocyte velocity from recorded image data.

Main Results:

• The protocol enables visualization of microvessels up to ~600 μm depth using MPLSM.
• Quantitative data on vascular parameters like density, length, and diameter can be reliably obtained.
• Red blood cell (RBC) flux can be measured on a vessel-by-vessel basis for hemodynamic assessment.

Conclusions:

• This protocol offers a robust framework for comprehensive vascular analysis in preclinical cancer research.
• The described methods facilitate detailed characterization of tumor angiogenesis and hemodynamics.
• The technique is adaptable for assessing therapeutic interventions targeting tumor vasculature.