目的 觀察電壓依賴性鈣通道是否作用于大鼠脊髓背角膠狀質層（SG）神經元大振幅微小興奮性突觸后電流的形成。 方法 選用成年雄性Sprague-Dawley（SD）大鼠，2%～3%異氟烷麻醉后，分離其腰骶部的脊髓，然后切片。采用全細胞電壓鉗技術，玻璃微電極的電阻為4~6 MΩ，鉗制電壓為?70 mV，記錄膠狀質層神經元微小興奮性突觸后電流（mEPSC）電流。將電流信號用Axopatch 200來放大并儲存于電腦。對照組和用藥結束后，持續采樣mEPSC電流30 s。mEPSC電流的頻率和振幅用Clampfit 8.1進行分析。 結果 鉗制電壓為?70 mV時，所有SG神經元均有自發性的EPSC。辣椒素增加mEPSC發生的頻率和波幅。鈷離子抑制辣椒素誘導的大振幅mEPSC。鈷離子抑制辣椒素誘導的mEPSC的平均振幅，而不抑制其發生頻率。 結論 電壓依賴性鈣離子通道參與了辣椒素引起的痛覺形成。
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.