Thromboxane A2-induced arrhythmias in the anesthetized rabbit.

Experiments were conducted in the anesthetized rabbit to investigate mechanisms for arrhythmias that occur after left atrial injection of the thromboxane A(2) (TxA(2)) mimetic U-46619. Arrhythmias were primarily of ventricular origin, dose dependent in frequency, and TxA(2) receptor mediated. The response was receptor specific since arrhythmias were absent after pretreatment with a specific TxA(2) receptor antagonist (SQ-29548) and did not occur in response to another prostaglandin, PGF(2alpha).