HETEROGENEITY OF RAT-LIVER AND SPLEEN MACROPHAGES IN GADOLINIUM CHLORIDE-INDUCED ELIMINATION AND REPOPULATION

Blockade of phagocytosis and selective elimination of macrophages (mphis) are generally accepted procedures for gaining knowledge about the function of mphis in vivo. This study demonstrates that intravenous injection of gadolinium chloride (GdCl3) not only blocks phagocytosis by rat liver mphis (Kupffer cells) but also selectively eliminates the large mphis situated in the periportal zone of the liver acinus. Repopulation of mphis starts at 4 days after injection. During repopulation, mphis are less vulnerable to GdCl3. When repopulation is complete, the new mphis show the same vulnerability as the original ones. Splenic mphis are less vulnerable to GdCl3 because only some of the red pulp mphis transiently disappear. The white pulp mphis are not affected. Repopulation occurs sooner than in liver. These results indicate that administration of GdCl3 is a suitable approach to studying the in vivo function of large Kupffer cells.