HAEMODYNAMIC EFFECTS OF LABETALOL-INDUCED HYPOTENSION IN THE ANAESTHETIZED DOG

Central haemodynamic changes and regional blood flow were studiedusing the microsphere technique, during labetalol-induced hypotensionin dogs anaesthetized with pentobarbitone and fentanyl. Labetalol15 mg kg^–1 decreased mean arterial pressure from an averageof 88 mm Hg to 47 mm Hg. Mean pulmonary arterial pressure wasunchanged. Cardiac output was reduced by decrease in strokevolume, while heart rate remained unchanged. Myocardial bloodflow decreased approximately in parallel with left ventricularwork. Perfusion of the brain and kidneys was unchanged.