Objective Increased transcytosis of low-density lipoprotein (LDL)across the endothelium and oxidation of LDL deposited within the subendothelial space are crucial early events in atherogenesis. C1q/TNF-related protein...Objective Increased transcytosis of low-density lipoprotein (LDL)across the endothelium and oxidation of LDL deposited within the subendothelial space are crucial early events in atherogenesis. C1q/TNF-related protein (CTRP) 5 is a novel secreted glycoprotein and its biological functions are largely undefined.展开更多
The experiments were perfomed on transvcrsus abdominis muscle of Elaphe dione by subendothelial recording. The results indicate that in snake motor nerve endings there exist four types of K* channels, i.e. voltage-dep...The experiments were perfomed on transvcrsus abdominis muscle of Elaphe dione by subendothelial recording. The results indicate that in snake motor nerve endings there exist four types of K* channels, i.e. voltage-dependent fast and slow K+ channels, Ca2 +-activated K+ channel and ATP-sensitive K+ channel, (i) The typical wave form of snake terminal current was the double-peaked negativity in standard solution. The first peak was at-tributed to Na influx (INa) in nodes of Ranvier. The second one was blocked by 3, 4-aminopyridine (3, 4-DAP) or te-traethylammonium (TEA), which corresponded to fast K+ outward current (IKF) through the fast K* channels in terminal part, (ii) After IKF as well as the slow K+ current (IKS) were blocked by 3, 4-DAP, the TEA-sensitive Ca2+-dependent K+ current (IK(Ca)) passing through Ca2+-activated K+ channel was revealed, whose amplitude depended on [K+ ]and [Ca2+ ] It was blocked by Ba2+ , Cd2+ or Co2+ . (iii) IK.F and IK(Ca) were blocked by TEA, while IK.S was retained. It was sensitive to 3,4-DAP, partially blocked by ethanol (200 mmol/L) or β-bungarotoxin (2 μmol/L), and enhanced by low pH (6.4-6.7). This is the first report that certain current component of motor nerve terminal is sensitive to pH in the range of 6.4-7.5. (iv) That diazoxide (200 μmol/L) increased the second negative peak and the effect was eliminated after further addition of glibenclamide (50 μmol/L) was taken as evidence for the presence of ATP-sensitive K+ current (IK ATP) at snake nerve terminal.展开更多
文摘Objective Increased transcytosis of low-density lipoprotein (LDL)across the endothelium and oxidation of LDL deposited within the subendothelial space are crucial early events in atherogenesis. C1q/TNF-related protein (CTRP) 5 is a novel secreted glycoprotein and its biological functions are largely undefined.
基金Project supported by the National Natural Science Foundation of China.
文摘The experiments were perfomed on transvcrsus abdominis muscle of Elaphe dione by subendothelial recording. The results indicate that in snake motor nerve endings there exist four types of K* channels, i.e. voltage-dependent fast and slow K+ channels, Ca2 +-activated K+ channel and ATP-sensitive K+ channel, (i) The typical wave form of snake terminal current was the double-peaked negativity in standard solution. The first peak was at-tributed to Na influx (INa) in nodes of Ranvier. The second one was blocked by 3, 4-aminopyridine (3, 4-DAP) or te-traethylammonium (TEA), which corresponded to fast K+ outward current (IKF) through the fast K* channels in terminal part, (ii) After IKF as well as the slow K+ current (IKS) were blocked by 3, 4-DAP, the TEA-sensitive Ca2+-dependent K+ current (IK(Ca)) passing through Ca2+-activated K+ channel was revealed, whose amplitude depended on [K+ ]and [Ca2+ ] It was blocked by Ba2+ , Cd2+ or Co2+ . (iii) IK.F and IK(Ca) were blocked by TEA, while IK.S was retained. It was sensitive to 3,4-DAP, partially blocked by ethanol (200 mmol/L) or β-bungarotoxin (2 μmol/L), and enhanced by low pH (6.4-6.7). This is the first report that certain current component of motor nerve terminal is sensitive to pH in the range of 6.4-7.5. (iv) That diazoxide (200 μmol/L) increased the second negative peak and the effect was eliminated after further addition of glibenclamide (50 μmol/L) was taken as evidence for the presence of ATP-sensitive K+ current (IK ATP) at snake nerve terminal.
