Burch R M, Halushka P V
J Clin Invest. 1980 Dec;66(6):1251-7. doi: 10.1172/JCI109976.
The effects of thromboxane B(2) and the stable prostaglandin endoperoxide analogs (15Z)-hydroxy - 9alpha - 11alpha - (epoxymethano)prosta - 5Z,13E - dienoic acid (U44069) and (15Z)-hydroxy -11alpha,9alpha-(epoxymethano) prosta-5Z,13E-dienoic acid (U46619) were tested on water flow across the toad urinary bladder. In the presence of indomethacin or meclofenamic acid, inhibitors of prostaglandin and thromboxane A(2) synthesis, thromboxane B(2) stimulated water flow in a dose-dependent manner. U44069 (1 muM) stimulated water flow from 3.6+/-0.8 to 12.4+/-1.2 mg/min per 10 cm(2) hemibladder surface area, while U46619 (1 muM) stimulated water flow from 2.8+/-1.0 to 21.8+/-2.0 mg/min per 10 cm(2). The prostaglandin endoperoxide/thromboxane A(2) antagonist trans- 13-azaprostanoic acid, an inhibitor of vasopressin-stimulated water flow, inhibited thromboxane B(2)- and U46619-stimulated water flow in a dose-dependent manner. The inactive cis-13-azaprostanoic acid did not inhibit vasopressin-stimulated water flow in untreated hemibladders and had no effect on U46619-stimulated water flow in indomethacin or meclofenamic acid pretreated hemibladders. U46619 (1 muM) enhanced vasopressin-stimulated water flow in indomethacin pretreated hemibladders, producing a significant parallel shift (P < 0.001) in the dose-response relationship to submaximal concentrations of vasopressin (0.1-0.6 mU/ml), while not affecting water flow stimulated by supramaximal concentrations of vasopressin (10 mU/ml). trans-13-Azaprostanoic acid abolished the potentiating effects of U46619 on vasopressin-stimulated water flow. These results show that thromboxane A(2)-like compounds stimulate water flow in the toad urinary bladder.
研究了血栓素B₂以及稳定的前列腺素内过氧化物类似物（15Z）-羟基-9α-11α-（环氧亚甲基）前列腺-5Z，13E-二烯酸（U44069）和（15Z）-羟基-11α，9α-（环氧亚甲基）前列腺-5Z，13E-二烯酸（U46619）对蟾蜍膀胱水转运的影响。在存在吲哚美辛或甲氯芬那酸（前列腺素和血栓素A₂合成抑制剂）的情况下，血栓素B₂以剂量依赖方式刺激水转运。U44069（1μM）使每10 cm²半膀胱表面积的水转运速率从3.6±0.8增加至12.4±1.2 mg/min，而U46619（1μM）使每10 cm²半膀胱表面积的水转运速率从2.8±1.0增加至21.8±2.0 mg/min。前列腺素内过氧化物/血栓素A₂拮抗剂反式-13-氮杂前列腺酸（一种血管升压素刺激水转运的抑制剂）以剂量依赖方式抑制血栓素B₂和U46619刺激的水转运。无活性的顺式-13-氮杂前列腺酸在未处理的半膀胱中不抑制血管升压素刺激的水转运，并且对吲哚美辛或甲氯芬那酸预处理的半膀胱中U46619刺激的水转运无影响。U46619（1μM）增强了吲哚美辛预处理的半膀胱中血管升压素刺激的水转运，在血管升压素亚最大浓度（0.1 - 0.6 mU/ml）的剂量反应关系中产生了显著的平行位移（P < 0.001），而不影响血管升压素超最大浓度（10 mU/ml）刺激的水转运。反式-13-氮杂前列腺酸消除了U46619对血管升压素刺激水转运的增强作用。这些结果表明，类血栓素A₂化合物刺激蟾蜍膀胱的水转运。
