Abstract: AIM: To study the effects of propofol on plasma membrane fluidity in PC12 cells and liposome, and its relevant mechanism. METHODS: Fluorescence depolarization method was used to measure values of fluorescence anisotropy, fluorescence polarization as well as microviscosity in PC12 cells and microviscosity in liposome continuously for 30 min. RESULTS: Propofol induced a significant decrease of fluorescence anisotropy, fluorescence polarization as well as microviscosity in PC12 cells, particularly in the first 5 min.After 5 min, the values of anisotropy were remained lower levels.Although propofol at concentration of 1 mg·L ^-1 had no effects on microviscosity in liposome, porpofol at concentration of 10 mg · L ^-1 and 100 mg·L ^-1 significantly decreased microviscosity in liposome. CONCLUTION: Propofol can significantly increase membrane fluidity in PC12 cells and liposome in a concertration-dependent manner, and the anesthetic effect of propofol may be resulted from changes of membrane fluidity and structure of neurocyte.

Key words: pharmacology, propofol, cells, PC12, liposome, membrane fluidity