The Effect of Synthetic Agonists and Antagonists of Cannabinoid Receptors on Migration of Neutrophils Elicited by Leukotriene B<SUB>4</SUB> in the Microvasculature of Hamster Cheek Pouch

This study was designed to investigate the effects of cannabinoid agonists and antagonists on neutrophil behaviors in response to inflammatory stimulation. The neutrophil behavior was observed in the microvasculature of hamster cheek pouch using a trans-illumination microscope. Superfusion of leukotriene B<SUB>4</SUB> caused an increase in the number of neutrophils migrating through the endothelium outside the venules. The migration induced by leukotriene B<SUB>4</SUB> was significantly attenuated in hamsters receiving WIN55212-2, a synthetic non-selective cannabinoid agonist, prior to the leukotriene B<SUB>4</SUB> superfusion. The inhibitory effect of WIN55212-2 was abolished by AM251, a selective CB<SUB>1</SUB> antagonist, and also by AM630, a selective CB<SUB>2</SUB> antagonist. These results suggest that augmentation of the CB<SUB>1</SUB> and CB<SUB>2</SUB> cannabinoid system could produce the inhibition of neutrophil migration and contribute to suppression of inflammatory derangement.