In the cat, intravenous injections of arachidonic acid or prostaglandin (PG)F2 alpha caused significant reductions in mean arterial pressure and heart rate which were eliminated or significantly lessened, respectively, by previous administration of indomethacin. The bradycardia to intravenous prostacyclin (PGI2) was unaffected by indomethacin. In cats with bilateral ligation of the carotid arteries to eliminate competition between systemic baroreflexes and cardiopulmonary reflexes, PGI2, PGF2 alpha and arachidonic acid caused significantly greater hypotension and bradycardia than in cats with intact carotid baroreflexes. The bradycardia to PGI2, PGF2 alpha and arachidonic acid was eliminated by bilateral vagal section or atropine. PGE1, PGE2 and nitroprusside caused dose-related falls in mean arterial pressure and a small tachycardia. In a small group of cats (7 of 67) nitroprusside also caused a reduction in heart rate which was eliminated by indomethacin. We conclude that the reflex bradycardia to PGF2 alpha, like that to arachidonic acid is, at least in part, the result of the stimulation of synthesis of another prostaglandin, most likely PGI2.
Nitroglycerin-induced severe hypotension and bradycardia in patients with acute myocardial infarction
Cardiovascular actions of prostaglanding F2alpha; 15-me-F2alpha; F1alpha; F2beta and F1beta in the cat
Increased activity in left ventricular receptors during hemorrhage or occlusion of caval veins in the cat. A possible cause of the vaso-vagal reaction
Behavioural and autonomic patterns evoked by stimulation of the lateral hypothalamic area in the cat
Some direct and reflex cardiovascular actions of prostacyclin (PGI2) and prostaglandin E2 in anaesthetized dogs
Ciprostene, a stable prostacyclin analog, produces peripheral vasodilation, platelet inhibition and increased clot dissolution in the cat
Intracoronary infusion of prostaglandin I2 attenuates arterial baroreflex control of heart rate in conscious dogs
Bradyarrhythmias are slow heart rates. Symptoms may include syncope, dizziness, fatigure, shortness of breath, and chest pains. Find the latest research on bradyarrhythmias here.