Qy. Gong et Gq. Luo, Effects of catalase and endothelin on anoxia-induced vasoconstriction of porcine basilar artery in vitro, ACT PHAR SI, 20(1), 1999, pp. 43-46
AIM: To study whether anoxia-induced vasoconstriction was related to the re
lease of endothelin (ET). METHODS: Acute anoxia was induced by gassing the
organ chamber with 95 % N-2 + 5 % CO2. Changes in tension of porcine basila
r arterial ring was recorded. RESULTS: Anoxia-induced increases in tension
were 0.21 g +/- 0.08 g and 0.24 g +/- 0.09 g under basal tension and during
ET 3 nmol.L-1-induced contractions, respectively. In the rings tension did
not further augment following the increase of ET from 100 to 300 nmol.L-1
acute anoxia did cause further increase in tension of 0.16 g +/- 0.10 g (n
= 4). Catalase 800 and 2400 kU.L-1 decreased the anoxia-induced contraction
, with inhibitory rate of 33 % +/- 7 % and 47 % +/- 9 %, respectively. CONC
LUSION: Anoxia-induced vasoconstriction was related to release of hydrogen
peroxide from endothelial cells.