Fig. 4. Composite left pulmonary vascular pressure–flow (LPQ) plots in eight dogs at baseline and after U46619 preconstriction (*P < 0.01) in the conscious state and during enflurane anesthesia. Compared with the conscious state, enflurane had no net effect on the baseline LPQ relationship. The dose of U46619 was titrated to achieve the same degree of preconstriction in the conscious and enflurane-anesthetized states.