Objective To investigate the variation of fentanyl concentration and the gene expression and activity of rat intestinal cytochrome P450 3A1 in anhepatic phase. Methods The experiment was comprised of 2 steps. Step 1: The rats were randomly divided into experimental group (group A2, underwent occlusion of the hepatic portal) and control group (group A1), with 10 rats in each group. Fentanyl blood concentration was analyzed by LC/MS/MS. Step 2: The rats were randomly divided into group B1 (control), group B2 and group B3 (the rats underwent devascularization of the hepatic portal for 30 or 60 min). The levels of CYP3A1 in rat small intestine were assessed with RT-PCR and the enzymic activity of CYP3A1 was detected by fluorometry. Results Fentanyl concentration in anhepatic phase dropped more slowly in group A2 than group A1 (P

Objective To observe the effect of dexmedetomidine on plasma SDF-1 level in in hepatic portal occlusion operation.Methods Fifty patients with live cancer undergoing elective partial hepatectomy were selected,no gender limitation,aged 42 to 71,body mass index(BMI) 18.5 ～ 26.0 kg/m2,ASA grade Ⅱ or Ⅲ.The patients were randomly divided into 2 groups(n=25):control group and dexmedetomidine group.The dexmedetomidine group was performed the pump injection of dexmedetomidine 1 μg/kg at 15 min before induction of anesthesia.After induction the rate was changed to 0.4μg · kg-1 · h-1 until 15 min before the end of operation;the control group adopted the same method for conducting continuous intraverous infusion of the same capaci ty of 0.9％ sodium chloride.The peripheral venous blood was collected in 2 groups at preoperative 1 h (T0),postoperative 1 h (T1),postoperative 1 d (T2),postoperative 3 d(T3).The plasma SDF-1 level was detected by using enzyme-linked immunosorbent assay(ELISA).Results There was no statistically significant difference in liver resection range,blood loss,first porta hepatis vessel occlusion time,anesthesia time and plasma SDF-1 level before surgery between the two groups (P＞0.05).Compared with pre-operation,plasma SDF-11evel at T1,T2,T3 time point was significantly increased (P＜0.05).The plasma SDF-1 level at T1,T2,T3 time point in the dexmedetomidine group was lower than that in the control group(P＜0.05).Conclusion SDF-1 expression is significantly increased during perioperative period in the patients with hepatic portal occlusion operation,and intraoperative continuous dexmedetomidine can significantly reduce the SDF-1 level,which inhibits the chemotaxis and accumulation of inflammatory ceils to some extent.

Objective The biological half-life in vivo of local anesthesia is short, high concentration in local tissue is in-clined to cause central nerve and cardiovascular toxicity due to the drug absorption into blood by blood vessels.The research was to pre-pare the poly ( lactide-co-glycolide) nanoparticle loaded with ropivacaine ( RVC-PLGA-NPS) , optimize its process, and determine its characteristics in vitro. Methods An oil-in-water emulsion solvent evaporation technique was adopted to prepare the RVC-PLGA-NPS.The formulation was optimized by central composite design/response surface method(CCD-RSM), with the encapsulation effi-ciency( EE) , drug loading( DL) and particle size as the indexes.Research was also made on itsin vitro release by fitting different model equations. Results The acquired nanoparticals were smooth, with the mean particle size (331.21±2.11) nm, DL (13.81±1.35)%and EE (74.82±2.53)%.The accumulative release rate of the nanoparticals was about 73%in 96 h, which showed that Higuchi func-tion fitted the release curve. Conclusion The RVC-PLGA-NPS made by emulsion solvent evaporation technique have obvious drug-release behaviour in vitro.

Objective To dynamically observe the SDF-1 level in plasma,bone marrow,liver,lung and kidney,and to investigate their significance in obstructive jaundice and its complications. Method 48 male SD rats weighing about 200g were randomly divided into Sham group and CBDL group. The serum ALT ,AST and se-rum total bilirubin(TBIL)were detected at 7 d,14 d and 21 d after operation. General condition of rats in the two groups were observed. ELISA was applied in detecting expression of SDF-1 in plasma and supernate of tissue ho-mogenate. And mRNA expression of SDF-1 at different time was detected by qPCR assay. Results ALT,AST,TB increased rapidly after CBDL operation,the difference was significant compared with Sham group(P <0.05). The SDF-1 expression of plasma,liver tissue,lung tissue in CBDL rats at different time points were significantly higher than in Sham group. No significant difference was found in renal tissue. SDF-1 expression of bone marrow in 7 d,14 d,21 d was significantly lower in CBDL group than in Sham group. Conclusion Expression of SDF-1 in liver and lung tissues of obstructive jaundice rats significantly increased ,and decreased in marrow bone. This change may promote related stem cells mobilization and contribute to the pathological changes of obstructive jaun-dice.

Objective To evaluate the effects of melatonin on the excitability of pyramidal neurons in the prefrontal cortex and the role of melatonin receptor 1 (MT1 R)-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling pathway.Methods Brains were obtained from male SpragueDawley rats between 14 and 21 days after birth.The brain slices of 350-μm thick were prepared and placed in artificial cerebrospinal fluid.The brain slices were divided into 5 groups (n =6 each) using a random number table method:control group (C group),melatonin group (M group),MT1/2R antagonist luzindole plus melatonin group (L+M group),MT2R antagonist 4P-PDOT plus melatonin group (P+M group) and PKA inhibitor Rp-cAMPS plus melatonin group (R+M group).Cells were perfused for 2 min with artificial cerebrospinal fluid in group C.Cells were perfused for 2 min with 1 μmol/L melatonin in group M.Cells were perfused for 2 min with the mixture of 1 μmol/L MT1/2R antagonist luzindole and 1 μmol/L melatonin in group L+M.Cells were perfused for 2 min with the mixture of 1 μmol/L MT2R antagonist 4P-PDOT and 1 μmol/L melatonin in group P+M.In group R+M,1 mmol/L PKA inhibitor Rp-cAMPS was continuously added to the pipette solution,and cells were perfused for 2 min with 1 μmol/L melatonin.The whole-cell patch-clamp technique was used to record the membrane potential and clamp current of pyramidal neurons in the prefrontal cortex.Results Compared with group C,the clamp current was significantly increased,and the membrane potential was decreased in group M (P＜0.05).Compared with group M,the clamp current was significantly decreased,and the membrane potential was increased in L + M and R + M groups (P＜0.05),and no significant change was found in the clamp current or membrane potential in group P+M (P＞0.05).Conclusion Melatonin inhibits the excitability of pyramidal neutrons in the prefrontal cortex,and the mechanism is related to activating MT1 R-cAMP-PKA signaling pathway.

Objective To evaluate the relationship between prefrontal cortex and propofol-induced cognitive dysfunction in rats. Methods SPF healthy male Sprague-Dawley rats, weighing 300-350 g, aged 16 weeks, were used in this study. Thirty rats in which catheters were successfully implanted into the prefrontal lobe were divided into 2 groups ( n=15 each ) using a random number table method: control group (group C) and propofol group (group P). In group P, 50μmol/L propofol 0. 5μl was microinjected into the prefrontal cortex at day 7 after operation, and the equal volume of normal saline was given instead in group C. T-maze test and open field test were performed at 15 min after administration. Results Com-pared with group C, the correct rate of selection in T-maze was significantly decreased ( P＜0. 05) , and no significant change was found in the total locomotor or number of rearing in open field test in group P ( P＞0. 05) . Conclusion Prefrontal cortex may be involved in propofol-induced cognitive dysfunction in rats.

Analgesia, Epidural ; methods ; Esophagectomy ; methods ; Humans ; Male ; Middle Aged