Temporal study of carrageenan-induced PMN migration in mice

The time course of polymorphonuclear neutrophil (PMN) migration in an experimental inflammatory granuloma induced by carrageenan in the mice was studied at 6 different times of the day. Compared to saline, the number of PMN increased as soon as 240 min and reached high level at 480 min when migration was induced by carrageenan. The data showed circadian variations in the time course of cell migration. After 240 and 360 minutes of migration, the number of PMN was highest in the cell trap implanted at 09.00 whereas minimum values were obtained at 01.00. After 480 minutes of implantation, the PMN migration was maximal when the carrageenan experiment was performed at 05.00 and minimum values were obtained at 13.00. Thus, a significant rhythm was demonstrated in the time course of PMN migration.