ABSTRACT
Objective To investigate the effect of propofol anesthesia on the expression of β-secretase 1 (BACE1) and content of anyloid beta protein 1-42 (Aβ1-42) in the neonatal rat hippocampus.Methods Ninety Sprague-Dawley rats,aged 7 days,weighing 12-16 g,were randomly divided into 3 groups ( n =30 each):control group (group C),single dose of propofol anesthesia group (group SP),and repeated doses of propofol anesthesia group (group RP).Group C received intraperitoneal normal saline 7.5 ml/kg once a day for 7 consecutive days.Group SP received normal saline 7.5 ml/kg once a day for 6 consecutive days and propofol 75 mg/kg on 7th day.Group RP received propofol 75 mg/kg once a day for 7 consecutive days.Six rats in each group were chosen at 15 min after the end of injection on 7th day and blood samples were taken from the left ventricle for determination of the blood glucose level and for blood gas analysis.Eight animals in each group were sacrificed on 1st,3rd and 7th day after the end of injection on 7th day to determine the expression of BACE1 (using Western blot) and content of Aβ1-42 in the hippocampus (by ELISA).Results Compared with groups C and SP,the expression of BACE1 was up-regulated and the content of Aβ1-42 was significantly increased at each time point in group RP ( P ＜ 0.01 ).There was no significant difference in the expression of BACE1 and content of Aβ1-42 at each time point between groups C and SP ( P ＞ 0.05).Conclusion Repeated doses of propofol up-regulate the expression of BACE1 and increase the content of Aβ1-42 in neonatal rat hippocampus,which may be one of the mechanisms by which propofol leads to long-term cognitive dysfunction.Single dose of propofol does not have the effect.
ABSTRACT
Objective To investigate the effects of different modes of one-lung ventilation (OLV) on hemodynamies in the patients undergoing thoracic operation.Methods Forty-five adult patients undergoing thoracic surgery,were randomly allocated into 3 groups based on the modes of OLV used ( n =15 each):intermittent positive pressure ventilation ( IPPV,VT 6-8 ml/kg,RR 10-14 bpm,I:E 1:2) group,IPPV + positive end-expiratory pressure (PEEP) group and IPPV + continuous positive airway pressure (CPAP) group.Double-lumen tube was inserted.Conrrect positioning was verified by fiberoptic bronchoscopy.The patients were mechanically ventilated.PETCO2 was maintained at 35-45 mm Hg.In group IPPV + PEEP,OLV was performed for 30 min with PEEP of 5 cm H2O and then for another 30 min with PEEP of 10 cm H2O.In group IPPV + CPAP,OLV was performed with IPPV in the lung on the ventilated side and with CPAP of 5 cm H2O in the lung on the operated side (for 1 h).MAP,HR,cardiac output (CO),cardiac index ( CI),stroke volume (SV),and stnoke volume index (SVI) were recorded before induction of anesthesia,at 10 min after intubation,at 30 min of two-lung ventilation,at 30 min and 1 h of OLV,and at the end of operation ( T1-6 ).Arterial blood samples were taken at T1,2,4-6 for blood gas analysis.The levels of blood glucose and lactate were measured.Oxygen delivery ( DO2 ) and DO2 index ( DO2I) were calculated.Results Compared with IPPV group,SV,SVI,CO,CI,DO2 and DO2I were significantly decreased at T4,5 ( P ＜ 0.05),and no significant change was found in the levels of blood glucose and lactate in group IPPV + PEEP,and no significant change was found in the parameters mentioned above in group IPPV + CPAP ( P ＞ 0.05).Compared with IPPV + PEEP group,SV,SVI,CO,CI,DO2 and DO2I were significantly increased at T4,5 ( P ＜ 0.05),and no significant change was found in the levels of blood glucose and lactate in group IPPV + CPAP ( P ＞ 0.05).Conclusion It exerts no influence on hemodynamics using OLV with IPPV in the lung on the ventilated side and with CPAP of 5 cm H2O in the lung on the operated side,however,OLV with IPPV + PEEP can result in hemodynamic fluctuation,but the degree of fluctuation is lesser and DO2 can be maintained in the patients undergoing thoracic operation.
ABSTRACT
ObjectiveTo investigate the effect of propofol repeated anesthesia on the expression of CaMK Ⅱ α in the hippocampus in neonatal rats.MethodsThirty-two SD rats aged 7 days weighing 12-16 g were randomly divided into 2 groups (n =16 each): group C received intraperitoneal 0.9％ normal saline 7.5 ml/kg once a day for 7 days and group P received propofol 75 mg/kg once a day for 7 days.Learning and memory function were assessed using Morris warier maze at 28 days old of rats.The animals were sacrificed at 24 h after the tests and brain tissues were removed.The expression of CaMK Ⅱ α and phosphorylated CaMK Ⅱ α (pCaMK Ⅱ α) in hippocampal CAI region were determined by immunochemistry and Western bolt.ResultsCompared with group C,the escape latency was significantly prolonged,space exploration time shortened and expression of CaMK Ⅱ α and pCaMK Ⅱ α down-rugulated in group P than in group C( P ＜ 0.01 ).ConclusionPropofol repeated anesthesia decreases congnitive function through down-regulating the expression and inhibiting the activity of CaMK Ⅱ α in hippocampus in neonatal rats.