RESUMEN
Objective:To explore the effects and possible mechanism of liraglutide on hypoxia and high glucose-induced oxidative stress injury in cardiomyocytes. Methods:The neonatal rat cardiomyocytes were separated and cultured in vitro. The hypoxia and high glucose-induced injury model was established in neonatal rat cardiomyocytes. The cells were divided into six groups:the normal control group, liraglutide control group, hypoxia and high glucose model group, liraglutide treatment group, GLP-1R antagonist group and hyperosmotic control group. The metabolic ability of the cells was detected by MTT assay, the activities of LDH and CK-MB were detected by colorimetric method,SOD activity and MDA content were determined by xanthine oxidase method and thiobarbituric acid method,ROS level was measured by chemiluminescence method. The mRNA and protein expression of adaptor protein p66Shc was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Results:Compared with those in the normal control group, the cells in hypoxia and high glucose model group had poorly metabolic ability,the content of LDH, CK-MB, MDA and ROS increased (P < 0.01), the activity of SOD decreased (P <0.01), and the expression of adaptor protein p66Shc greatly increased(P <0.01). After the treatment with liraglutide,the above mentioned parameters were all improved(P < 0.01). Exendin(9-39),an antagonist of GLP-1R,attenuated the protective effect of liraglutide. Conclusion:Liraglutide has a protective effect on cardiomyocytes by down-regulating adaptor protein p66Shc expression and reducing ROS formation.
RESUMEN
Objective:To establish a determination method for the content and entrapment efficiency of ropivacaine hydrochloride-loaded multivesicular liposomes. Methods: The separation of the multivesicular liposomes from the free drug was achieved by low-speed centrifugation. The concentration of ropivacaine hydrochloride in the supernatant and the multivesicular liposomes was determined by HPLC, and the entrapment efficiency was calculated. Results: The linear range of ropivacaine hydrochloride was 1. 0-80. 0μg· ml-1(r=0. 999 8). The average recovery was 99. 95% and RSD was 0. 72%(n=9). The content and entrapment efficiency of three batches of ropivacaine hydrochloride-loaded multivesicular liposomes was within the range of 99. 1%-100. 3% and 80. 06%-82. 14%, respectively. Conclusion:The method is simple and accurate, and can be used in the determination of content and entrapment efficien-cy of ropivacaine hydrochloride-loaded multivesicular liposomes.