Kinetics of changes in peritoneal cell populations following acute inflammation

Abstract

The kinetics of macrophage (MΦ) recruitment to the peritoneum following the induction of acute inflammation by thioglycollate broth (TG) was evaluated after prelabeling resident MΦ with the fluorescent cell tracking dye, PKH-1. Most of the PKH-1-labeled resident MΦ disappeared from the recoverable peritoneal cell population within the first hour after injection of TG. This disappearance coincided with the inflammatory influx of neutrophils (PMNs) and was sustained for at least 5 days after administration of TG, although the PMN number had returned to resident levels by this time. PKH-1-labeled peritoneal MΦ were observed again in most animals at 7 days after injection of TG. The number of labeled MΦ recovered at 7 days was approximately twice the number of resident peritoneal MΦ in control animals which did not receive the TG broth. These additional MΦ may include progeny of either the resident MΦ or other local MΦ precursors, such as omental MΦ, which were labeled by the PKH-1 injection.