Role of thromboxane receptor activation in the bronchospastic response to endothelin.

摘要: Abstract The selective TxA 2 /PGH (TP) receptor antagonist, SQ 30, 741, was used to test the hypothesis that TP-receptor activation contributes reactivity of airways and isolated trachea endothelin-1 (ET-1). Dose-dependent contractions guinea pig tracheal strips ET-1 in vitro were unaffected by either 741 (1 μM) or indomethacin (2.8 μM). In contrast, maximal bronchospastic responses (increases resistance decreases dynamic lung compliance) anesthetized pigs (.05 1.5 nmole/kg i.v.) blocked >90% mg/kg i.v.). Concurrent increases arterial blood pressure leukocyte counts induced 741. rats, (1.5 did not affect mechanics, but cause biphasic leukopenia which unaltered These data demonstrate there is considerable species variability response ET-1, pigs, this repsonse caused predominantly TP-receptors.