目的 观察电压依赖性钙通道是否作用于大鼠脊髓背角胶状质层（SG）神经元大振幅微小兴奋性突触后电流的形成。 方法 选用成年雄性Sprague-Dawley（SD）大鼠，2%～3%异氟烷麻醉后，分离其腰骶部的脊髓，然后切片。采用全细胞电压钳技术，玻璃微电极的电阻为4~6 MΩ，钳制电压为?70 mV，记录胶状质层神经元微小兴奋性突触后电流（mEPSC）电流。将电流信号用Axopatch 200来放大并储存于电脑。对照组和用药结束后，持续采样mEPSC电流30 s。mEPSC电流的频率和振幅用Clampfit 8.1进行分析。 结果 钳制电压为?70 mV时，所有SG神经元均有自发性的EPSC。辣椒素增加mEPSC发生的频率和波幅。钴离子抑制辣椒素诱导的大振幅mEPSC。钴离子抑制辣椒素诱导的mEPSC的平均振幅，而不抑制其发生频率。 结论 电压依赖性钙离子通道参与了辣椒素引起的痛觉形成。
ObjectiveTo systematically review the incidence and influencing factors of early enteral nutritional feeding interruptions in critically ill patients. MethodsThe PubMed, Web of Science, Embase, Cochrane Library, CNKI, WanFang Data and CBM databases were electronically searched to collect observational studies on the early enteral nutritional feeding interruptions in critically ill patients from inception to January 2, 2024. Two reviewers independently screened literature, extracted data and assessed the risk of bias of the included studies. Meta-analysis was then performed by using Stata 17.0 software. ResultsA total of 12 studies including 1 121 patients were included. Meta-analysis showed that the incidence of early enteral nutritional feeding interruptions in critically ill patients was 75.0% (95%CI 64.0% to 84.0%). Influenced by feeding intolerance, airway management, tube problems, radiological examination, and endoscopy, surgery and so on, interruptions of early enteral nutritional feeding frequently occur in critically ill patients. ConclusionCurrent evidence shows that early enteral feeding interruptions in critically ill patients are affected by many factors, and the incidence is high. Due to the limited quality and quantity of the included studies, more high-quality studies are needed to verify the above conclusion.