MICROSCOPY Vol.46▶No.3 2011

Imaging and Quantification of Plasma Leakage from Microvessels by Using Intravital Lectin Injection

Shunichi Morikawa, Toshiyuki Watanabe and Taichi Ezaki

Abstract: Plasma leakage, caused by the hyper-permeability of blood vessel wall, is significant in the context of angiogenesis such as in regenerating tissues or tumors. We have developed a simple method to visualize blood vessels under a confocal laser scanning microscope by intravenous injection of fluorescent-conjugated tomato lectin that binds to glycocalyx of endothelia. Applying this method to the microcirculatory beds which contain hyper-permeable blood vessels, plasma leakage can be clearly visualized as well as the actual three-dimensional structure of the blood vessel networks, since lectin leaks out from the vessel wall together with plasma elements. Furthermore, by using “IMARIS”, a software program linked with Carl Zeiss confocal microscopes, fine three-dimensional images can be reconstructed from the confocal data, in which the volume of leaked lectin within a fixed area can be easily quantified. In this paper, we describe the practical procedure for the observation and quantification of plasma leakage in microcirculatory beds along with a concrete example of wound-healing animal model.

Key words: lectin, hyper-permeability, plasma leakage, three-dimensional imaging, IMARIS