Hemodynamic response of mice challenged by intravenous injection of AA. (A) Changes in blood pressure after intravenous AA treatment with (- - -) and without (—) prior infusion of SQ29548. Mice were anesthetized and blood pressure was continuously monitored till MAP was in stable readouts. AA (40 mg/kg) was injected at time 0. When AA was injected without SQ29548, all the WT mice (n = 4) developed cardiac arrest at around 90 to 120 seconds and died at 300 seconds when MAP monitoring was stopped. All TXAS–/– mice (n = 4) survived and MAP was recorded for 10 minutes. All mice pretreated with SQ29548 (2 mg/kg) also survived after AA challenge and their MAP was also monitored for 10 minutes. Blood pressure was expressed as change in MAP (ΔMAP) before and after AA infusion. *The statistical P values were analyzed by analysis of variance (ANOVA) for TXAS–/– mice with and without SQ29548 and were 0.05, 0.02, 0.04, 0.02, 0.05, and 0.02 for 300, 360, 420, 480, 540, and 600 seconds, respectively. (B) Changes in plasma TXA2 after AA infusion. Plasma from mice at normal and steady-state condition (n = 11) and 5 minutes after infusion of AA (n = 4) was prepared from citrated blood containing indomethacin. Plasma 2,3-dinor TXB2 was measured by an EIA kit. Error bars represent ±1 SD.
