作者:Elena Sanz、Luis Monge、Nuria Fernández、María Angeles Martínez、Juan B. Martínez-León、Godofredo Diéguez、Angel Luis García-Villalón
DOI:10.1038/sj.bjp.0704670
日期:2002.5
Urocortin, an endogenous peptide structurally related to corticotropin‐releasing factor (CRF), has potent cardiovascular effects, suggesting that it may be of significance in cardiovascular regulation. The objective of this study was to analyse the effects of urocortin and its action mechanisms on human blood vessels.
To this, 3 mm long segments from human saphenous veins were prepared for isometric tension recording in an organ bath.
In the segments at basal resting tone, urocortin did not produce any effect, but in the segments precontracted with endothelin‐1 (1 – 10 nM), urocortin (1 pM – 10 nM) produced concentration‐dependent relaxation.
This relaxation was not modified by the inhibitor of nitric oxide synthase NG‐nitro‐L‐arginine methyl ester (L‐NAME, 100 μM), but it was potentiated by the cyclo‐oxygenase inhibitor meclofenamate (10 μM) and it was reduced by the inhibitors of high‐conductance Ca2+‐dependent potassium channels tetraethylammonium (TEA, 10 mM) and charybdotoxin (100 nM).
These results indicate that human saphenous veins are very sensitive to urocortin, which produces vascular relaxation by a mechanism independent of nitric oxide and dependent of high‐conductance Ca2+‐dependent potassium channels, and that it may be opposed by the release of vasoconstrictor prostanoids. Therefore, urocortin may be of significance for regulation of the venous circulation in humans.
British Journal of Pharmacology (2002) 136, 90–94; doi:10.1038/sj.bjp.0704670
尿皮质素(Urocortin),是一种与促肾上腺皮质激素释放因子(CRF)结构相关的内源性肽类物质,具有显著的心血管效应,提示其可能在心血管调节中具有重要意义。本研究旨在分析尿皮质素对人血管的作用及其作用机制。为此,从人股静脉中取3 mm长的血管段,准备在器官浴中进行等张张力记录。在基线静息状态下,尿皮质素未产生任何效果,但在预先用内皮素-1(1 – 10 nM)收缩的血管段中,尿皮质素(1 pM – 10 nM)产生了浓度依赖性的舒张作用。这种舒张作用不受一氧化氮合酶抑制剂NG‐硝基‐L‐精氨酸甲酯(L‐NAME,100 μM)的影响,但在环氧化酶抑制剂甲芬酸(10 μM)存在下被增强,并在高导电性Ca2+依赖性钾通道抑制剂四乙基铵(TEA,10 mM)和Charybdotoxin(100 nM)存在下被抑制。这些结果表明,人股静脉对尿皮质素非常敏感,尿皮质素通过一种与一氧化氮无关、但依赖于高导电性Ca2+依赖性钾通道的机制诱导血管舒张,同时可能被释放的缩血管型前列腺素所抵消。因此,尿皮质素可能在人类静脉循环调节中具有重要意义。British Journal of Pharmacology(2002)136,90–94;doi:10.1038/sj.bjp.0704670