This study examined adhesion molecules on peripheral leukocytes following a 30-min infusion of the beta-adrenergic agonist isoproterenol in 23 healthy subjects. In response to isoproterenol, the number of CD8 +CD62L- T cells and both CD62L+ and CD62L-natural killer (NK) (CD3 CD16+ 56+) cells increased markedly in circulation (p < 0.001). In addition, the surface density of CD62L was significantly lower on both CD8+ and CD4+ T cells (p < 0.001). Plasma levels of soluble CD62L remained unchanged, arguing against an isoproterenol-induced shedding of L-selectin. In contrast to CD62L, the surface density of the beta2 integrin LFA-1 (CD11a) was higher on circulating lymphocytes (p < 0.001) (but not monocytes or lymphocytes) post-infusion. Isoproterenol also led to a mobilization of memory/activated CD8+CD29high T cells (p < 0.01), but had no significant effect on the number of circulating CD8+ CD45RA+ CD62L+ naïve T cells. beta blockade with the non-specific antagonist propranolol eliminated these isoproterenol-induced effects.