兔回肠纵肌肾上腺素能爱体作用分析及递质间的相互作用

实验采用兔离休回肠纵肌标本，观察了经典递质去甲肾上腺素（ＮＥ．）和乙酰胆碱（ＡＣｈ．）对兔回肠纵肌收缩的效应及其相互关系，并对其作用的受体途径进行了分析．实验结果表明；（１）ＡＣｈ能加强回肠纵肌收缩，ＮＥ有抑制作用，但二者的作用可以变化；（２）酚妥拉明使收缩力量增加，心得安使其减弱；（３）ＮＥ能加强Ａｃｈ的兴奋作用，这一加强作用可放心得安阻断．ＡＣｈ对ＮＥ的抑制作用无明显影响．以上结果提示，兔回肠纵肌α肾上腺素能受体介导抑制，β受体介导兴奋，ＮＥ加强Ａｃｈ的兴奋效应与β受体密切相关．     

The in vitro interaction of CmeA with CmeC

The membrane fusion protein CmeA and the outer membrane channel CmeC,two important components of CmeABC system in Campylobacter jejuni,were expressed in Escherichia coli.After Ni-NTA and ion exchange columns purification,size exclusion chromatography showed that CmeA primarily existed as trimer and CmeC existed as monomer.Then the interaction between CmeA and CmeC was analyzed by dithiobis(succinimidyl propionate)(DSP)chemical crosslinking,pull-down assay on a Ni-NTA column,and isothermal titration calorimetry(ITC)measurement.The results clearly showed the CmeA–CmeC complex band,which confirmed the interaction in vitro and this interaction is independent of substrate and CmeB.It suggests that the mechanism underlying CmeABC function in C.jejuni is similar to that of AcrABTolC in E.coli.     

Reverberatory activity in neuronal networks in vitro

It has been proposed that during cognitive processes, "online" memory traces in the brain are carried by reverberatory activity in neuronal circuits. However, the nature of such reverberation has remained elusive from experimental studies, largely due to the enormous complexity of intact circuits. Recent works have attempted to address this issue using cultured neuronal network and have revealed new dynamic properties of network reverberation as well as the underlying cellular mechanisms. These results demo...     

豚鼠离体小肠电活动与机械收缩

以小肠电活动和环肌张力、纵肌张力为指标，用同步记录的方法研究了豚鼠离体小肠电活动与环肌张力、纵肌张力之间的关系，结果表明：（１）豚鼠离体小肠的电活动包括慢波与峰波；（２）豚鼠离体小肠始终存在着节律性张力活动，其环肌收缩与纵肌收缩的关系表现为拮抗收缩、共同收缩、交互抑制等形式；（３）峰波可增加收缩力，峰波的个数、振幅与小肠张力呈正变关系，尤其与环肌收缩的对应关系更为显著．（４）慢波可触发收缩，尤其是纵肌收缩．在没有峰波仅有慢波时，亦可有收缩活动甚至活跃的收缩活动．