Adenosine signaling in outer medullary descending vasa recta.
Adenosine signaling in outer medullary descending vasa recta.
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外髓降直血管中的腺苷信号传导。
DOI：
10.1152/ajpregu.2001.280.3.r854
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Pallone,TL
中科院分区：
文献类型：
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作者：
Silldorff,EP;Pallone,TL
我们检测了外髓直降血管（OMDVR）的扩张是否由cAMP、一氧化氮（NO）和环氧合酶（考克斯）介导。腺苷（A; cAMP类似物8-溴腺苷3′，5 ′-环一磷酸（10− 10至10− 4 M）可模拟ANG II（10− 9 M）预收缩OMDVR的血管舒张作用，并可被腺苷酸环化酶抑制剂SQ-22536逆转。腺苷（10− 4 M）刺激OMDVR cAMP产生超过3倍。用NG-硝基-l-精氨酸甲酯和NG-单甲基-l-精氨酸（10− 4 M）阻断NO合酶不影响腺苷血管舒张。腺苷诱导的内皮细胞胞浆钙瞬变很小。吲哚美辛（10− 6 M）逆转腺苷诱导的OMDVR扩张，OMDVR由ANG II、内皮素、4-溴-钙离子载体A23187或碳环血栓烷A2预收缩。相反，选择性A2受体激活扩张内皮素预收缩的OMDVR，即使在消炎痛的存在下。我们的结论是，腺苷的OMDVR血管扩张涉及cAMP和考克斯，但没有NO。考克斯阻滞剂不能完全抑制选择性A2受体介导的OMDVR扩张。
We tested whether dilation of outer medullary descending vasa recta (OMDVR) is mediated by cAMP, nitric oxide (NO), and cyclooxygenase (COX). Adenosine (A; 10−6M)-induced vasodilation of ANG II (10−9M)-preconstricted OMDVR was mimicked by the cAMP analog 8-bromoadenosine 3′,5′-cyclic monophosphate (10−10to 10−4M) and reversed by the adenylate cyclase inhibitor SQ-22536. Adenosine (10−4M) stimulated OMDVR cAMP production greater than threefold. NO synthase blockade withNG-nitro-l-arginine methyl ester andNG-monomethyl-l-arginine (10−4M) did not affect adenosine vasodilation. Adenosine induced endothelial cytoplasmic calcium transients that were small. Indomethacin (10−6M) reversed adenonsine-induced dilation of OMDVR preconstricted with ANG II, endothelin, 4-bromo-calcium ionophore A23187, or carbocyclic thromboxane A2. In contrast, selective A2-receptor activation dilated endothelin-preconstricted OMDVR even in the presence of indomethacin. We conclude that OMDVR vasodilation by adenosine involves cAMP and COX but not NO. COX blockade does not fully inhibit selective A2receptor-mediated OMDVR dilation.