The effects of a thromboxane A2 receptor antagonist on neurologic recovery after 15 min complete global brain ischemia in dogs

The effects of a thromboxane A₂ receptor antagonist (anti-TXA₂; ONO-3708) on the neurologic recovery after 15min complete cerebral ischemia were investigated in dogs. Complete cerebral ischemia was achieved by occlusion of the trunk of the aorta, the superior and the inferior caval vein. Seventeen dogs were divided into 2 groups; 1) control group (no drug, n = 9), 2) Anti-TXA₂ group (anti-TXA₂ 200mcg·kg^–1 in iv bolus soon after recirculation followed by continuous infusion at a rate of 10mcg·kg^–1·min^–1 for 3 days, n = 8). EEG, auditory brainstem response (ABR), middle latency response (MLR), and somatosensory evoked potential (SEP) recordings were obtained before ischemia, 120min after re-circulation and on the 7th day after ischemia. The neurologic recovery score (NRS) were determined on the 3rd and the 7th day. Impaired EEG score was significantly higher in the anti-TXA₂ group on 7th day after ischemia (P < 0.05). Anti-TXA₂ increased the reappearance rates of the ABR-Vth (P < 0.05) and the SEP-N₃ waves (P < 0.01) at 120min after ischemia. The survival rate tended to be higher in the anti-TXA₂ group. However, NRS did not significantly differ in the groups.(Takahashi M, Iwatsuki N, Ono K, et al.: The effects of a thromboxane A₂ receptor antagonist on neurologic recovery after 15min complete global brain ischemia in dogs. J Anesth 5: 73–78, 1991)