Cells of the immune system express mostly beta-2 adrenergic receptors, and to a lesser degree beta-1 receptors (9, 10), so pharmacological blockade requires use of a non specific blocker which can block both types of receptors. The beta-antagonist propranolol was chosen for this experiment since it is a non specific beta-blocker, capable of blocking both types of receptors, as well as extensive clinical experience with this drug and the fact that it is a relatively safe drug. The COX-2 inhibitor chosen is Etodlac (Etopan), which has the advantage of being a selective COX-2 inhibitor,synthesized during injury and inflammation, with little effect on the COX-1 enzyme, which is associated with ongoing maintenance of tissues.