Zhang Li-min, Niu Chun-yu, Zhao Zi-gang, Si Yong-hua, Zhang Yu-ping
Institute of Microcirculation, Hebei North University, Hebei, China.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue. 2012 Aug;24(8):457-60.
To investigate the mechanism of ATP-sensitive potassium channel (K(ATP)) on nitride oxide (NO) regulating contractile activity of isolated lymphatics from hemorrhagic shock (HS) rats.
Eighty - four Wistar rats were randomly divided into control group (n=6), HS 0.5-hour group (n=36), HS 2-hour group (n=42). A segment of thoracic duct of rats was adopted for isolated lymphatics after HS, then the HS 0.5-hour and 2-hour lymphatics were incubated combined or respectively with K(ATP) inhibitor glibenclamide (Gli), opener of K(ATP) pinacidil (Pin), NO donor L-arginine (L-Arg), protein kinase A (PKA) inhibitor H-89, PKA donor 8-bromine-cyclic adenosine monophosphate (8-Br-cAMP), nitricoxide synthase (NOS) inhibitor N-nitro-L-arginine methyl ester (L-NAME), soluble guanylyl cyclase (sGC) inhibitor 1 h-[1,2,4]-oxadiazole-[4,3-a]- quinoxalin-1-one (ODQ), protein kinase G (PKG) inhibitor KT-5823 (named as HS 0.5 h, HS 0.5 h + L-Arg, HS 0.5 h + L-Arg + H-89, HS 0.5 h + L-Arg + Gli, HS 0.5 h + 8-Br-cAMP, HS 0.5 h + 8-Br-cAMP + Gli and HS 2 h, HS 2 h + L-NAME, HS 2 h + L-NAME + Pin, HS 2 h + ODQ, HS 2 h + ODQ + Pin, HS 2 h + KT-5823, HS 2 h + KT-5823 + Pin, n=6). By lymphatic perfusion in vitro, contractile frequency (CF) was recorded, and contractile amplitude (CA), tonic index (TI) and fractional pump flow (FPF) were calculated.
The results suggested that the CF, TI, FPF of HS 0.5-hour lymphatics were significantly increased compared with control group, and the CF, TI, FPF decreased significantly when incubated with L-Arg. H-89 could deteriorate the decreased effect of L-Arg on CF and FPF, and Gli could deteriorate the decreased effect of L-Arg on FPF. When the HS 0.5-hour lymphatics incubated with 8-Br-cAMP, the CF and FPF were all decreased significantly, and when the HS 0.5-hour lymphatics incubated with 8-Br-cAMP and Gli, the CF was significantly higher than HS 0.5 h + 8-Br-cAMP group, and the TI and FPF decreased significantly compared with HS 0.5-hour group. The CF, FPF, TI of HS 2-hour lymphatics were significantly decreased compared with control group. L-NAME could increase the CF, TI, FPF; ODQ could increase the CF, TI; KT-5823 could increase the CF and FPF; when incubated with Pin respectively, the CF and FPF when incubated with L-NAME were decreased, the CF, TI and FPF when incubated with ODQ were decreased, in addition, the CA was recovered as level of control group, the CF and FPF when incubated with KT-5823 were decreased.
K(ATP) involved in NO modulating pumping function of isolated lymphatics of HS rats, and the effect may be relative to the signal pathway of NO-cAMP-PKA and NO-cGMP-PKG.
探讨三磷酸腺苷敏感性钾通道（K(ATP)）在一氧化氮（NO）调节失血性休克（HS）大鼠离体淋巴管收缩活动中的作用机制。
将84只Wistar大鼠随机分为对照组（n = 6）、HS 0.5小时组（n = 36）、HS 2小时组（n = 42）。采用大鼠胸段淋巴管制备离体淋巴管，HS 0.5小时和2小时组的淋巴管分别或联合K(ATP)抑制剂格列本脲（Gli）、K(ATP)开放剂匹那地尔（Pin）、NO供体L-精氨酸（L-Arg）、蛋白激酶A（PKA）抑制剂H-89、PKA供体8-溴环磷酸腺苷（8-Br-cAMP）、一氧化氮合酶（NOS）抑制剂N-硝基-L-精氨酸甲酯（L-NAME）、可溶性鸟苷酸环化酶（sGC）抑制剂1H-[1,2,4]-恶二唑-[4,3-a]-喹喔啉-1-酮（ODQ）、蛋白激酶G（PKG）抑制剂KT-5823进行孵育（分别命名为HS 0.5小时组、HS 0.5小时 + L-Arg组、HS 0.5小时 + L-Arg + H-89组、HS 0.5小时 + L-Arg + Gli组、HS 0.5小时 + 8-Br-cAMP组、HS 0.5小时 + 8-Br-cAMP + Gli组以及HS 2小时组、HS 2小时 + L-NAME组、HS 2小时 + L-NAME + Pin组、HS 2小时 + ODQ组、HS 2小时 + ODQ + Pin组、HS 2小时 + KT-5823组、HS 2小时 + KT-5823 + Pin组，n = 6）。通过体外淋巴管灌注，记录收缩频率（CF），并计算收缩幅度（CA）、张力指数（TI）和分泵流量（FPF）。
结果显示，HS 0.5小时组淋巴管的CF、TI、FPF较对照组显著升高，与L-Arg孵育后CF,T I,FPF显著降低。H-89可减弱L-Arg对CF和FPF的降低作用，Gli可减弱L-Arg对FPF的降低作用。HS 0.5小时组淋巴管与8-Br-cAMP孵育后，CF和FPF均显著降低，与8-Br-cAMP和Gli共同孵育时，CF显著高于HS 0.5小时 + 8-Br-cAMP组，TI和FPF较HS 0.5小时组显著降低。HS 2小时组淋巴管的CF、FPF、TI较对照组显著降低。L-NAME可升高CF、TI、FPF；ODQ可升高CF、TI；KT-5823可升高CF和FPF；分别与Pin共同孵育后，与L-NAME孵育时的CF和FPF降低，与ODQ孵育时的CF、TI和FPF降低，此外，CA恢复至对照组水平，与KT-5823孵育时的CF和FPF降低。
K(ATP)参与NO对HS大鼠离体淋巴管泵功能的调节，其作用可能与NO-cAMP-PKA和NO-cGMP-PKG信号通路有关。
