Chronological Changes in Tip Cells during Sprouting Angiogenesis of Development of the Retinal Vasculature in Newborn Mice.

The number of tip cells increased to a greater extent in the superficial vascular plexus of veins versus arteries until P-6. Consequently, there are more vessel areas and vascular branch points near retinal veins versus arteries. Arterial tip cells are longer and thinner than the shorter and thicker venous tip cells.