论文部分内容阅读
AIM:To investigate the relationship betweenhyposmotic membrane stretch and muscarinic receptoragonist-induced depolarization of membrane potentialin antral gastric circular myocytes of guinea-pig.METHODS:Using whole cell patch-clamp techniquerecorded membrane potential and current in singlegastric myocytes isolated by collagenase.RESULTS:Hyposmotic membrane stretch hyperpolarizedmembrane potential from-60.0mV±1.0mV to-67.9mV±1.0mV.TEA(10mmol/L),a nonselective potassiumchannel blocker significantly inhibited hyposmoticmembrane stretch-induced hyperpolarization.After KCIin the pipette and NaCI in the external solution werereplaced by CsCI to block the potassium current,hyposmotic membrane stretch depolarized the membranepotential from-60.0 mV±1.0mV to-44.8 mV±2.3mV(P<0.05),and atropine(1 μmol/L)inhibited thedepolarization of the membrane potential.Muscarinicreceptor agonist Carbachol depolarized membranepotential from-60.0mV±1.0mV to-50.3 mV±0.3mV(P<0.05)and hyposmotic membrane stretchpotentiated the depolarization.Carbachol inducedmuscarinic current(I_(cch))was greatly increased byhyposmotic membrane stretch.CONCLUSION:Hyposmotic membrane stretchpotentiated muscarinic receptor agonist-induceddepolarization of membrane potential,which is relatedto hyposmotic membrane stretch-induced increase ofmuscarinic current.
AIM: To investigate the relationship betweenhyposmotic membrane stretch and muscarinic receptoragonist-induced depolarization of membrane potential in antral gastric circular myocytes of guinea-pig. METHODS: Using whole cell patch-clamp techniquerecorded membrane potential and current in singlegastric myocytes isolated by collagenase .RESULTS: Hyposmotic membrane stretch hyperpolarizedmembrane potential from -60.0 mV ± 1.0 mV to -67.9 mV ± 1.0 mV. TEA (10 mmol / L), a nonselective potassium channel blocker significantly inhibited hyposmotic membrane stretch-induced hyperpolarization. After KCI in the pipette and NaCI in the external solution were remodeled by CsCI to block the potassium current, hyposmotic membrane stretch depolarized the membrane potential from -60.0 mV ± 1.0 mV to -44.8 mV ± 2.3 mV (P <0.05), and atropine (1 μmol / L) inhibited thedepolarization of the membrane potential. Muscarinic receptor agonist Carbachol depolarized membrane potential from -60.0 mV ± 1.0 mV to -50.3 mV ± 0.3 mV (P <0.05) and hyposmotic membrane st retchpotentiated the depolarization. Carbachol induced muscarinic current (I_ (cch)) was greatly increased by hyposmotic membrane stretch. CONCLUSION: Hyposmotic membrane stretch spotentiated muscarinic receptor agonist-induced depolarization of membrane potential, which is relatedto hyposmotic membrane stretch-induced increase of muscarinic current.