{'fraction_non_alphanumeric': 0.05215646940822467, 'fraction_numerical': 0.0, 'mean_word_length': 5.565789473684211, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
[Properties of peroxynitrite-induced relaxation in rabbit pulmonary artery in vitro].

Vasodilatory properties of exogenous peroxynitrite (ONOO(-)) and effects of endothelial cells on ONOO(-) induced relaxation were investigated in isolated rabbit pulmonary arterial rings (PARs). In pre-contracted PARs, ONOO(-) gave rise to vasodilation in a dose-dependent manner, which was significantly higher than that of decomposed ONOO-. In contrast, relaxation of PARs to ONOO(-) was lower, as compared with sodium nitroprusside (SNP) or acetylcholine(ACh). ONOO(-) induced more significant relaxation in denuded endothelial PARs than in intact endothelial PARs. Relaxation of PARs to repetitively administered ONOO(-) appeared progressively decreased. Under this experimental condition, relaxation of PARs to ACh remained unchanged after administrating ONOO(-). These results suggest that ONOO(-) causes weak relaxation in pulmonary artery, which is down regulated by endothelium and is of tachyphylaxis.