Biphasic effect of SNP on opossum esophageal longitudinal muscle: involvement of cGMP and eicosanoids.
Biphasic effect of SNP on opossum esophageal longitudinal muscle: involvement of cGMP and eicosanoids.
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SNP 对负鼠食管纵肌的双相作用：cGMP 和类二十烷酸的参与。
DOI：
10.1152/ajpgi.1993.265.2.g403
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Goyal,RK
中科院分区：
文献类型：
--
作者：
Saha,JK;Hirano,I;Goyal,RK
研究了含一氧化氮（NO）化合物对离体负鼠食管纵行平滑肌的作用。硝普钠（SNP）和正宗的NO产生了一个双相的浓度依赖性舒张-收缩序列在食管纵肌（ELM），但只有浓度依赖性舒张食管下括约肌（LES）和食管环肌没有效果。鸟苷3 '，5'-环一磷酸（cGMP）的细胞膜可渗透类似物8-溴鸟苷3 '，5'-环一磷酸（8-BrcGMP）也在ELM中产生舒张-收缩序列和LES的舒张。鸟苷酸环化酶抑制剂亚甲蓝（MB）和LY-83583增加静息张力，对SNP诱导的ELM舒张无显著影响。然而，它们消除了SNP和NO诱导的ELM收缩。环氧合酶抑制剂吲哚美辛对ELM舒张无影响，但可消除SNP、NO和8-BrcGMP引起的ELM收缩。这些研究表明，在ELM中，1）SNP、真实NO和8-BrcGMP引起双相舒张-收缩序列; 2）MB和LY-83583阻断收缩，但不阻断与SNP和NO相关的舒张;和3）吲哚美辛阻断收缩，但不阻断由于SNP、NO和8-BrcGMP引起的舒张。这些结果表明，在ELM中，NO供体发挥抑制作用，这在很大程度上是cGMP的独立性和兴奋作用，通过cGMP依赖性途径，涉及内源性类花生酸的环氧合酶途径。
Effects of nitric oxide (NO)-containing compounds on opossum esophageal longitudinal smooth muscle in vitro were examined. Sodium nitroprusside (SNP) and authentic NO produced a biphasic concentration-dependent relaxation-contraction sequence in the esophageal longitudinal muscle (ELM) but only a concentration-dependent relaxation of the lower esophageal sphincter (LES) and no effect in the esophageal circular muscle. A cell membrane-permeable analogue of guanosine 3',5'-cyclic monophosphate (cGMP), 8-bromoguanosine 3',5'-cyclic monophosphate (8-BrcGMP) also produced relaxation-contraction sequence in the ELM and relaxation of the LES. The guanylate cyclase inhibitors methylene blue (MB) and LY-83583 increased resting tone and had no significant effect on SNP-induced relaxation of ELM. However, they abolished the SNP- and NO-induced contraction of ELM. The cyclooxygenase inhibitor indomethacin had no effect on ELM relaxation and abolished the contractions due to SNP, NO, and 8-BrcGMP. These studies show that in the ELM 1) SNP, authentic NO, and 8-BrcGMP cause a biphasic relaxation-contraction sequence; 2) MB and LY-83583 blocked contraction but not the relaxation associated with SNP and NO; and 3) indomethacin blocked contractions but not the relaxation due to SNP, NO, and 8-BrcGMP. These results suggest that in the ELM, NO donors exert an inhibitory action that is largely cGMP independent and an excitatory action via a cGMP-dependent pathway involving endogenous eicosanoids of the cyclooxygenase pathway.