Motility of rabbit alveolar cells: role of unsaturated fatty acids.

A mechanism for the specific accumulation of macrophages in alveoli or other biologic cavities following injury is presented. The data herein indicate that unsaturated fatty acids, ie, linoleic and linolenic acids, which accumulate in rat pleura following injection of carrageenan or during incubation of rabbit alveolar macrophages (AMs), strongly activate migration in vitro of AMs but not of human polymorphonuclear leukocytes (PMNLs). Other anionic lipids, ie, phosphatidylglycerol, as well as various nonspecific proteins, such as gelatin, or albumin were also shown to be potent activators of migration of AMs and not of PMNLs. These observations suggest that the elaboration of unsaturated fatty acids, as well as of nonspecific proteins, is responsible for the specific accumulation of macrophages in injured body spaces, such as alveoli or pleura.