Ultrasound contrast agent, Levovist microbubbles are phagocytosed by Kupffer cells-In vitro and in vivo studies.

Phase contrast microscopy showed that Levovist microbubbles were phagocytosed by cultured Kupffer cells and moved gradually toward the nucleus from the cell surface. They were diminished in size and disappeared within 30min by diffusion of the gas contained within the microbubbles. In an in vivo study, confocal laser scanning microscopy demonstrated that Levovist microbubbles were trapped and phagocytosed by Kupffer cells. No microbubbles were observed attached to the sinusoidal endothelium. Our findings suggest that liver-specific images obtained following intravenous injection of Levovist are composed of signals from microbubbles phagocytosed by Kupffer cells.