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目的:探讨一氧化氮对豚鼠胃窦环行肌钙敏感钾电流的影响。方法:采用全细胞式的膜片箝方法,用精胺、硝普盐、3-吗啉-悉尼酮亚胺(SIN-1)作为一氧化氮供体。结果:外向钾电流被四乙铵(1 mmol·L~(-1))和ChTx(200nmol·L-1)显著抑制。在穿孔膜式条件下,精胺(100 μmol·L~(-1))、SIN-1(200 μmol·L~(-1))、硝普盐(100 μmol·L~(-1))均增加钙敏感钾电流。1μmol·L~(-1)亚甲蓝完全阻断硝普盐与SIN-1导致的增加效应。结论:一氧化氮增加豚鼠胃窦环行肌钙敏感钾电流,该效应可能通过环磷酸鸟苷介导。
Objective: To investigate the effect of nitric oxide on calcium-sensitive potassium currents in gastric antral circular muscle of guinea pigs. Methods: Whole-cell patch-clamp method was used as nitric oxide donor with spermine, nitroprusside and 3-morpholine-sydrineimine (SIN-1). Results: Outward potassium currents were significantly inhibited by tetraethylammonium (1 mmol·L -1) and ChTx (200 nmol·L -1). Under perforated membrane conditions, spermine (100 μmol·L -1), SIN-1 (200 μmol·L -1), nitroprusside (100 μmol·L -1) Increased calcium-sensitive potassium current. 1μmol·L -1 methylene blue completely blocked the effects of nitroprusside and SIN-1. CONCLUSION: Nitric oxide increases calcium-sensitive potassium currents in the gastric antral circular muscle of guinea pigs, which may be mediated by guanosine monophosphate.