Objectives Acidosis has an inhibitory effect on the inactivation of Kv1.4 ΔN channel through the position H508. So in order to show the effects of glutamic acid on the mutant Kv 1.4 channel that lacks N-type inactiva...Objectives Acidosis has an inhibitory effect on the inactivation of Kv1.4 ΔN channel through the position H508. So in order to show the effects of glutamic acid on the mutant Kv 1.4 channel that lacks N-type inactivation （Kv1.4 Δ2-146）, we studied in the expression system of the Xenopus oocytes. Methods The two-electrode voltage-clamp technique （TEV） was used to record the currents. Results Acidosis increased fKv1.4 Δ2-146 C-type inactivation. After application of glutamic acid （1 mmol/L） to Kv1.4 Δ2-146 increased C-type inactivation further, changed inactivation time constants from （2.02 ± 0.39 s ） to （1.71 ± 0.23 s） （P〈 0.05） at ＋50mv, and shifted the steady-state inactivation curves of Kv1.4 ΔN to positive potential, which was from （-44.30 ± 0.59 mV） to （-39.88 ± 0.29 mV）（P〈0.05）. and slowed the rate of recovery from inactivation, which was from （1.64 ± 0.19 s） to （1.91 ± 0.23 s）（P〈 0.05）. Conclusions Together, these results suggest that 1 mmol/L glutamic acid accelerates the C-type inactivation of Kv1.4 ΔN in pH 6.8.展开更多
文摘目的:观察Ghrelin对球囊损伤大鼠颈动脉狭窄的干预作用,初步探讨其作用机制。方法:选择健康雄性SD大鼠30只,建立大鼠颈总动脉球囊损伤模型,制模后随机分为假手术组、模型组、Ghrelin组,各为10只。腹腔注射给药30 d后取损伤侧颈总动脉,行天狼星红染色并测量管腔面积以判定血管腔狭窄程度;Westernblot检测血管壁Mfn-2蛋白表达。结果:(1)术后30 d,模型组血管内弹力板断裂,内膜及中膜尤其是中膜增生严重,管腔狭窄(46.53±9.78)%,Ghrelin组中膜增生及狭窄程度为(75.62±10.08)%组间比较,差异具有统计学意义(P<0.05)(2)球囊扩张损伤颈动脉可明显下调Mfn-2蛋白表达(1.243±0.129)vs(0.634±0.097)。Ghrelin则能明显上调Mfn-2的表达(0.824±0.049 vs 0.634±0.097),组间比较,差异具有统计学意义(P<0.05)。结论:Ghrelin可抑制球囊损伤大鼠颈总动脉所致的管腔狭窄,同时能上调颈动脉平滑肌Mfn-2的表达,Ghrelin可能是通过上调Mfn-2的表达来抑制再狭窄的。
文摘Objectives Acidosis has an inhibitory effect on the inactivation of Kv1.4 ΔN channel through the position H508. So in order to show the effects of glutamic acid on the mutant Kv 1.4 channel that lacks N-type inactivation （Kv1.4 Δ2-146）, we studied in the expression system of the Xenopus oocytes. Methods The two-electrode voltage-clamp technique （TEV） was used to record the currents. Results Acidosis increased fKv1.4 Δ2-146 C-type inactivation. After application of glutamic acid （1 mmol/L） to Kv1.4 Δ2-146 increased C-type inactivation further, changed inactivation time constants from （2.02 ± 0.39 s ） to （1.71 ± 0.23 s） （P〈 0.05） at ＋50mv, and shifted the steady-state inactivation curves of Kv1.4 ΔN to positive potential, which was from （-44.30 ± 0.59 mV） to （-39.88 ± 0.29 mV）（P〈0.05）. and slowed the rate of recovery from inactivation, which was from （1.64 ± 0.19 s） to （1.91 ± 0.23 s）（P〈 0.05）. Conclusions Together, these results suggest that 1 mmol/L glutamic acid accelerates the C-type inactivation of Kv1.4 ΔN in pH 6.8.
