Algara-Suárez Paola, Espinosa-Tanguma Ricardo
Departamento de Fisiología y Farmacología, Facultad de Medicina, Universidad Autónoma de San Luis Potosi, S.L.P. 78210, San Luis Potosí, Mexico.
Biochem Biophys Res Commun. 2004 Feb 6;314(2):597-601. doi: 10.1016/j.bbrc.2003.12.136.
In this study, guinea pig tracheal smooth muscle pre-contracted with histamine was relaxed by the addition of 100microM 8Br-cGMP, a non-hydrolyzable and cell-permeable analog for cGMP. This effect was not sensitive to cGMP-dependent protein kinase (PKG) inhibitors, whereas it was partially blocked by cAMP-dependent protein kinase (PKA) inhibitors. The relaxation observed was also reverted up to 50+/-8.5% by iberiotoxin, a selective inhibitor of large conductance, calcium-activated potassium channels (BK(Ca)). Our results indicate that there exists a crosstalk mechanism between cAMP and cGMP signaling pathways which lead to relaxation of guinea pig tracheal smooth muscle and also that BK(Ca) channels are involved to a certain extent in this phenomenon.
在本研究中，用组胺预收缩的豚鼠气管平滑肌通过添加100微摩尔的8-溴环鸟苷酸（8Br-cGMP，一种不可水解且可透过细胞的环鸟苷酸类似物）而松弛。这种效应对环鸟苷酸依赖性蛋白激酶（PKG）抑制剂不敏感，而部分被环磷酸腺苷依赖性蛋白激酶（PKA）抑制剂阻断。所观察到的松弛也被iberiotoxin（一种大电导钙激活钾通道（BK(Ca)）的选择性抑制剂）逆转高达50±8.5%。我们的结果表明，环磷酸腺苷（cAMP）和环鸟苷酸（cGMP）信号通路之间存在一种相互作用机制，该机制导致豚鼠气管平滑肌松弛，并且BK(Ca)通道在这一现象中也有一定程度的参与。
