心内膜调控溶血磷脂酰胆碱的正性肌力作用

ENDOCARDIAL ENDOTHELIUM MODULATES LYSOPHOSPHATIDYLCHOLINE INDUCED POSITIVE INOTROPISM

观察心内膜对溶血磷脂酰胆碱（ＬＰＣ）引起离体豚鼠乳头肌正性肌力作用的影响。结果表明：ＬＰＣ对离体豚鼠乳头肌具有正性肌力作用，并呈浓度依赖性和时间依赖性；选择性去除乳头肌心内膜后，ＬＰＣ对去除心内膜乳头肌的正性肌力作用增强。

In isolated guinea pig papillary muscles, the endocardial endothelium (EE) was selectively damaged by exposing the muscles to a flow of dry air for 30s for removal of function EE. The results showed that LPC induced positive inotropic effect on papillary muscles was observed in a concentration and time dependent manner PT after 15 mins' exposure to 5, 10 and 20μmol·L -1 lysophosphatidylcholine (LPC) was increased by 104±7%, 110±6% and 124±10%, respectively . The positive inotropic effect of 10mmol·L -1 LPC on papillary muscles denuded of EE was significantly enhanced (PT: 163±23% vs 130±17% after exposing to LPC for 30 min). Scanning and transmission electronic microscopic studies exhibited signs of EE damage of papillary muscles incubated with LPC 10 μmol·L -1 for 30 minutes, such as disruption of gap junction between overlapping EE cells, retraction of the cell borders, fenestration on the EE, and denudation of the subjacent basal lamina. The present study suggests that the EE may affect the LPC induced contractibility of papillary muscle via its barrier function signs, in addition, the present data provides further evidence that LPC may be a trigger for some kind of biological active factor release form EE.