Effect of centrally administered isoproterenol on peripheral tissue proinflammatory cytokine production. Rats were injected i.c.m. with either saline or isoproterenol (β-agonist) and sacrificed 30, 60, or 120 min later (n=7/group). Values from saline-injected animals were averaged and presented as 0 min. Additional rats were injected i.c.m. with propranolol (β-antagonist) immediately prior to isoproterenol administration and sacrificed 60 min later (60+P; n=4/group). Pituitary, spleen, and liver tissues were dissected and A) IL-1, B) IL-6, and C) TNF-α measured. Bars represent group averages +/− SEM. * represents p < 0.05 compared to saline-injected controls. # represents p < 0.05 compared to isoproterenol-injected animals sacrificed at 60 min.