Kinetics of Kupffer cells as shown by parabiosis and combined autoradiographic/immunohistochemical analysis.

Leucocytes from syngeneic rats were labeled with tritiated thymidine and donor and recipient rats were connected by a bilateral arteriovenous shunt. Based on the time-dependent label index and labeling intensity, it was concluded that Kupffer cells, the resident macrophages of the liver, have a half-life of 12.4 days and originate from monocytes undergoing one mitosis within 8.4 days after immigration into the liver. The labeled cells were easily identified as Kupffer cells by their selective immunoreactivity with the monoclonal antibody Ki-M2R which is specific for phagocytosing macrophages in the rat. The applicability of combined autoradiography/immunohistochemistry for the identification of other poorly defined macrophage subpopulations is shown.