Fig. 5. Isoproterenol dose–response relationship measured in eight dogs after U46619 preconstriction in the conscious state and during enflurane anesthesia is shown. Vasodilator response to isoproterenol is expressed as the percentage decrease in U46619 preconstriction (defined in Methods section). Isoproterenol-induced pulmonary vasodilation (*P < 0.05) was not altered during enflurane anesthesia compared with the conscious state.