Chronic propranolol treatment decreases pulmonary artery pressure in conscious dogs.
Daily administration of propranolol to 9 chronically instrumented, trained dogs for 2 weeks caused significant (p less than 0.05) decreases in heart rate (70 +/- 8 to 57 +/- 6 beats/min), cardiac output (3.6 +/- 0.3 to 2.9 +/- 0.2 liters/min), pulmonary arterial pressure (15.7 +/- 0.5 to 10.0 +/- 0.5 mm Hg) and total pulmonary vascular resistance (4.6 +/- 0.6 to 3.3 +/- 0.4 units). Nadolol, a structurally dissimilar beta-adrenergic receptor antagonist, caused a similar decrease in total pulmonary resistance. Acute meclofenamate administration did not return to normal pulmonary arterial pressure and resistance in the dogs chronically treated with beta-adrenergic receptor blockers. We therefore conclude that chronic beta-adrenergic receptor blockade lowered pulmonary arterial pressure and resistance by a mechanism independent of cyclooxygenase. In addition, chronic beta-adrenergic receptor blockade did not affect the potential for hypoxic vasoconstriction.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002302:Cardiac Output / Q000187:drug effects; D004285:Dogs; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects; D000860:Hypoxia / Q000503:physiopathology; D007545:Isoproterenol / Q000494:pharmacology; D008469:Meclofenamic Acid / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects; D011433:Propranolol / Q000097:blood / Q000494:pharmacology*; D011651:Pulmonary Artery / Q000187:drug effects*; D013997:Time Factors; D014661:Vasoconstriction / Q000187:drug effects
D008469:Meclofenamic Acid; D011433:Propranolol; D007545:Isoproterenol