白三烯在犬离体基底动脉缺氧性收缩中的可能作用。

Possible role of leukotrienes in hypoxic contraction of canine isolated basilar artery.

Gu M, Elliott D A, Ong B Y, Bose D

Department of Pharmacology & Therapeutics, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.

Br J Pharmacol. 1991 Jul;103(3):1629-32. doi: 10.1111/j.1476-5381.1991.tb09839.x.

Abstract

Hypoxia reversibly increased isometric tension in unstimulated canine isolated basilar artery rings. 2. Nordihydroguaiaretic acid (NDGA; 5 x 10(-6) M), an inhibitor of lipoxygenase and quinacrine (10(-5) M), which blocks the release of arachidonic acid from phospholipids by inhibiting the enzyme phospholipase A2, blocked hypoxia-induced contractions. 3. The preferential leukotriene D4 (LTD4) antagonist, L-660,711, also inhibited the hypoxia-induced contractions in concentrations ranging from 10(-8) M to 10(-5) M. The effects seen were statistically significant (P less than 0.05). Two components of inhibition were seen. 4. Arachidonic acid (5 micrograms ml-1) caused contraction of the isolated basilar artery rings. This response was inhibited by NDGA (5 x 10(-6) M) and L-660,711 (10(-5) M). 5. The LTD4 (10(-8) M-10(-7) M)-induced contraction was relaxed by L-660,711 in a dose-dependent manner. Both the contraction caused by LTD4 as well as that caused by hypoxia were relaxed by 5 x 10(-6) M adenosine. 6. Leukotriene(s) may be involved in hypoxia-induced contraction of canine isolated basilar artery. However, they may not be the sole mediator(s).

摘要

缺氧可使未受刺激的犬离体基底动脉环的等长张力可逆性增加。2. 去甲二氢愈创木酸（NDGA；5×10⁻⁶ M），一种脂氧合酶抑制剂，以及奎纳克林（10⁻⁵ M），其通过抑制磷脂酶A2来阻断花生四烯酸从磷脂的释放，可阻断缺氧诱导的收缩。3. 选择性白三烯D4（LTD4）拮抗剂L - 660,711，在浓度范围为10⁻⁸ M至10⁻⁵ M时也能抑制缺氧诱导的收缩。观察到的效应具有统计学意义（P小于0.05）。出现了两种抑制成分。4. 花生四烯酸（5微克/毫升）可引起离体基底动脉环收缩。这种反应被NDGA（5×10⁻⁶ M）和L - 660,711（10⁻⁵ M）抑制。5. LTD4（10⁻⁸ M - 10⁻⁷ M）诱导的收缩被L - 660,711以剂量依赖性方式松弛。LTD4引起的收缩以及缺氧引起的收缩均被5×10⁻⁶ M腺苷松弛。6. 白三烯可能参与犬离体基底动脉的缺氧诱导收缩。然而，它们可能不是唯一的介质。