Vascular endothelial growth factor and basic fibroblast growth factor differentially modulate early postnatal...

Area of Science:

• Cardiovascular Biology
• Developmental Biology
• Molecular Medicine

Background:

• Coronary angiogenesis, the formation of new blood vessels in the heart, is critical for its function.
• Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are key regulators of blood vessel development.

Purpose of the Study:

• To investigate the roles of VEGF and bFGF in regulating coronary angiogenesis during early postnatal development.
• To determine how these growth factors influence capillary and arteriolar growth and the formation of the arteriolar tree hierarchy.

Main Methods:

• Administration of neutralizing antibodies against VEGF and bFGF to rats between postnatal days 5 and 12.
• Immunohistochemistry and Western blotting to assess protein levels.
• Stereological assessment of perfusion-fixed hearts to quantify vascular structures.

Main Results:

• Both anti-VEGF and anti-bFGF antibodies reduced VEGF protein levels and inhibited capillary growth.
• bFGF antibody, but not anti-VEGF, inhibited arteriolar growth.
• Combined antibody treatment reduced small arterioles and increased large arterioles, altering the vascular hierarchy.

Conclusions:

• Both VEGF and bFGF are essential modulators of capillary growth in early postnatal coronary angiogenesis.
• bFGF plays a significant role in promoting arteriolar growth.
• VEGF and bFGF interact to establish the normal hierarchical structure of the coronary arteriolar tree.