Objective To investigate the effects of different concentrations of isoflurane on cerebral cortex content of acetylcholine and the underlying mechanism.Methods Six adult male SD rats weighing 300-350 g were used in this study. The guide needle was inserted and micro-electrodes were implanted 2 days before experiment. At the beginning of the experiment the micro-analysis needles were inserted into cerebral cortex and the micro-electrodes were connected to HXD-1 multi-function monitor. Micro-dialysis liquid was collected and BIS and 95% SEF were recorded before and during isoflurane anesthesia at 0.6% , 1% and 1.4% (each concentration was maintained for 30 min) and at 1 h after isoflurane inhalation was discontinued. Acetylcholine and choline concentrations in micro-dialysis liquid were determined. Results Isoflurane reduced acetylcholine and choline concentrations in cerebral cortex and decreased BIS and 95% SEF values in a dose-dependent manner. At 1 h after isoflurane inhalation was discontinued the concentrations of acetylcholine and choline didn' t return to the baseline values but the BIS and SEF returned to the baseline values. The BIS and SEF value at the disappearance of corneal reflex was 44.2 ? 2.2 and 11.6 ? 1.7 respectively.Conclusion Our study shows that the central cholinergic system is involved in the mechanism of isoflurane anesthesia.

0.05, E tube), and increased by 177% and 212% with mechanical stimulation (bubbling) at 30th min and 60th min (P

Objective To examine the dyllamic changes in excitatory and inhibitory amino acid neurotransmitter release in the spinal cord in a rat model of incisional pain.Methods Twelve healthy adult male SD rats weighing 250-300g were anesthetized with intraperitoneal chloral hydrate 300 mg/kg.A loop microdialysis catheter was implanted into the subarachnoid space via the atlanto-occipital membrane and advanced for 8.5 cm candad until lumbar region.The animals were randomly divided into 2 groups(n=6 each): control group(C) and incisional pain group(I).Incisional pain was produced by the plantar incision in the tight hindpaw under 1.2% isoflurane in group I while group C received only anesthesia with 1.2% isoflurane.The microdialysis samples were collected before incision(To,baseline)at 3 h,1 d,2 d and 3 d after incision(T1-4) for determination of amino acid using HPLC.The pain behavior was assessed and scored (O=no pain,2=severe pain) at the above time paints.Results In group I the aspartate and glutamate concentrations in the microdialysis samples were significantly increased at 3 h after incision(T1) as compared with the baseline value at To and returned to the baseline level at l d(T2);the glyeine and r-amino butyric acid concentrations were signifieantly increased at ld (T2)and returned to the baseline level at 2 d(T3).The cumulated pain scores were significantly increased at 3 h,1 d and 2 d after incision and returned to baseline level at 3 d (T4) in group I.Conclusion The increased release of excitatory amino acid neurotransmitter in the early phase after incision may be involved in hyperalgesia while the increased release of inhibitory amino acid neurotransmitter in the later phase may be involved in the pain relief.

Objective To evaluate the effects of teriipressin on perioperative renal function in patients undergoing liver transplantation. Methods Forty ASA Ⅲ or Ⅳ patients (31 males and 9 females) aged 35-55 yr and weighing 46-81 kg were randomly divided into2 groups (n=20 each): terlipressin group and control group. The patients were premedicated with intramuscular midazolam 2- 3 mg and atropine 0.5 mg. Swan-ganz catheter was placed via the right internal jugular vein and the radial artery was cannulated. Electrocardiography (ECG), blood pressure (BP), heart rate (HR), central venous pressure (CVP) and pulmonary arterypressure (PAP) were monitored during general anesthesia. General anesthesia was induced with midazolam (0.1-0.2 mg/kg), fentanyl (5-10 μg/kg), propofol(1-2 mg/kg) and vecuronium (0.1 mg/kg) and maintained with 0.5%-1.5% isoflurane, propofol infusion at 2-5 mg·kg-1·h-1 and intermittent i.v. boluses of fentanyl and vecuronium. The patients were mechanically ventilated after tracheal intubation. In the terlipressin group, 2 mg of terlipressin was added to 50 ml of normal saline (NS) and was continuously infused at 10 ml/L from beginning of operation until the end of anhepatic phase, while in the control group, NS was infused only. Blood and urine samples were taken before operation(T0), at the end of anhepatic phase (T1), at the end of operation (T2), and on the 1st and 2nd day after operation (T3, T4)for determination of plasma angiotensin Ⅱ (AT- Ⅱ ), serumβ2-microglobulin (MG), blood urea nitrogen (BUN) and creatinine (Cr) concentrations and N-acetyl-βd-glucosaminidase (NAG) concentrations in the urine. Urine output was measured during pre-anhepatic, anhepatic and neo-hepatic phase and on the 1 st and2nd day after operation. Results The urinary NAG and serum β2-MG concentrations were significantly increased at T1 as compared with the baseline at T0in both groups. The urinary NAG, plasma AT-Ⅱ, serum β2-MG, BUN and Cr concentrations were significantly lower and theurinary output was significantly higher during T2-4 in the terlipressin group than in the control group. Conclusion Terlipressin has protective effects on renal function in patients undergoing orthotopic liver transplantation.

Objective To evaluate the feasibility of using stroke volume variation (SVV) as the left ventricular preload to draw the cardiac function curve.Methods Twenty-seven patients of both sexes,aged 18-64 yr,with body mass index of 18-30 kg/m2,of American Society of Anesthesiologists physical status Ⅱ (New York Heart Association Ⅱ),with abnormal cardiac function,scheduled for elective offpany coronary artery byp grafting,were enrolled in this study.Twenty-five patients,aged 18-64 yr,with body mass index of 18-30 kg/m2,of American Society of Anesthesiologists physical status Ⅰ (New York Heart Association Ⅰ),with normal cardiac function,scheduled for elective non-cardiac surgery,were also enrolled in this study.SVV and SV were monitored by using a FloTrac/VigileoTM system.The patients were in the supine position from the end of anesthesia induction to the beginning of surgery.After the hemodynamics was kept stable for 5 min,SVV and SV were recorded.6％ hydroxyethyl starch 130/0.4 500 ml was intravenously infused over 20 min.SVV and SV were recorded after volume expansion.Spearman rank-order correlation was used to analyze the relationship between SVV and SV.The quadratic regression analysis was used to draw the SVV-SV curve,and the SVV-SV curve was compared with the Frank-Starling curve.Results Compared with the value before volume expansion,SVV and HR were significantly decreased,and SV was increased after volume expansion in the patients with normal cardiac function,and SVV was decreased after volume expansion in the patients with abnormal cardiac function (P＜0.01).SVV was negatively correlated with SV in the patients with normal cardiac function,and r=-0.467 (P＜0.05).SVV was negatively correlated with SV in the patients with abnormal cardiac function,and r=-0.378 (P＜0.05).The mirror symmetry was found between the SVV-SV curve in the patients with normal cardiac function and the normal Frank-Starling curve,and the general trend was close.The symmetry was not detected between the SVV-SV curve in the patients with abnormal cardiac function and the Frank-Starling curve in the patients with decreased myocardial contractility,and the general trend was not close.Conclusion For the patients with normal cardiac function,SVV can be used as the left ventricular preload to draw the cardiac function curve.

Objective To investigate the effect of isoflurane anesthesia on the expression of amyloid β protein (Aβ) in hippocampus in aged rats.Methods Sixty-one healthy male SD rats,aged 18-19 months,weighing 400-500 g,were randomly divided into 3 groups:isoflurane group (group Ⅰ,n =31),control group (groupⅡ,n =20),and blank group (group Ⅲ,n =10).Group Ⅰ inhaled 1.4％ isoflurane for 2 h,and cognitive function was assessed at 5 d before and 2 d after anesthesia by Morris water maze.Group Ⅱ received Morris water maze text only.Group Ⅲ received no treatment.Group Ⅰ was divided into 2 subgroups according to whether the cognitive impairment occurred:cognitive impairment group (P subgroup) and no cognitive impairment group (NP subgroup).The animals were sacrificed immediately after the test.The hippocampus was isolated for determination of the levels of Aβ40 and Aβ42,β-secretase (BACE),insulin degrading enzyme (IDE)and neprilysin (NEP).Results There was no significant difference in the results of Morris water maze test before anesthesia among the 3 groups.There was no significant difference in the swimming velocity between group Ⅰ and group Ⅱ.The time of staying at the original platform quadrant was significantly shorter in P subgroup than in NP subgroup and Ⅱ group,and there was no significant difference in the time of staying at the original platform quadrant between NP subgroup and Ⅱ group.There was no significant difference in the levels of Aβ40 and Aβ42,BACE,NEP and IDE among the 5 groups,and between P subgroup and NP subgroup.Conclusion Isoflurane anesthesia has no effect on the expression of Aβ in the hippocampus,indicating that isoflurane-induced cognitive impairment is not related to Aβ pathway in aged rats.

Objective To investigate the effect of batroxobin combined with tranexamic acid on the perioperative bleeding and blood coagulation in the patients undergoing adolescent idiopathic scoliosis.Methods Eighty ASA Ⅰ or Ⅱ patients,aged 15-26 yr,weighing 41-56 kg,scheduled for elective adolescent idiopathic scoliosis,were randomly divided into 4 groups (n =20 each):normal saline group (group A),batroxobin group (group B),tranexamic acid group (group C) and batroxobin combined with tranexamic acid group (group D).0.9 ％ normal saline was infused after admission to the operating room in group A.Batroxobin 0.02 U/kg was infused at 20 min before skin incision,an increment of 0.02 U/kg was given every 2 h until the end of operation and the maximal dose was less than 1 U in group B.Tranexamic acid 20 mg/kg was injected immediately before skin incision,followed by infusion at 10 mg· kg-1 · h-1 until the end of operation in group C.In group D,batroxobin and tranexamic acid were given as the method described in B and C groups.The intraoperative blood loss,volume of autologous and allogeneic blood transfused,transfusion of fresh frozen plasma (FFP),and volume of drainage within 24 h after operation were recorded.Blood routine,prothrombin time (PT),activated partial thromboplastin time (APTT),fibrinogen (Fbi),thrombin time (TT),activated clotting time (ACT),clot rate (CR) and platelet function (PF) were measured.Deep vein thrombosis was detected at 1 week after operation.Results Compared with group A,the intraoperative blood loss,volume of allogeneic blood transfused,transfusion of FFP,volume of autologous blood transfused and volume of postoperative drainage were significantly reduced,and Plt and Fib were significantly increased at T2,3 in groups B,C and D,and PF was increased at T2 in group C,Hct,Plt,Fib and PF were increased and PT was prolonged at T2,3 in group D (P ＜ 0.05).Compared with group B,the intraoperative blood loss,volume of allogeneic blood transfused,transfusion of FFP,volume of autologous blood transfused and volume of postoperative drainage were significantly decreased and Hct,Plt,Fib and PF were increased at T2,3 in group D,and the volume of postoperative drainage was increased and Plt increased at T2,3 was in group C (P ＜ 0.05).Compared with group C,the intraoperative blood loss,volume of allogeneic blood transfused,volume of autologous blood transfused,volume of postoperative drainage and transfusion of FFP were significantly decreased and Hct,Plt,Fib and PF were significantly increased at T2,3 in group D (P ＜ 0.05).No patients developed blood coagulation disorder and deep vein thrombosis.Conclusion Batroxobin combined with tranexamic acid can significantly reduce the intraoperative blood loss and volume of allogeneic blood transfused and improve the blood coagulation,and the efficacy is superior to that of either alone for the patients undergoing adolescent idiopathic scoliosis.

Objective To evaluate the blood-saving effect of combination of hemocoagulase artox for injection and tranexamic acid (TXA) in patients undergoing off-pump coronary artery bypass grafting (OPCABG).Methods Eighty ASA Ⅱ patients (NYHA Ⅰ or Ⅱ),aged 50-70 yr,weighing 50-100 kg,scheduled for elective OPCABG,were randomly divided into 4 groups (n =20 each):control group (group C),hemocoagulase atrox for injection group (group H,n =20),TXA group (group T) and hemocoagulase atrox for injection + ·TXA group (group HT).Hemocoagulase atrox 0.04 U/kg (the highest dose 4 U) was injected at 20 min before skin incision,and additional hemocoagulase atrox 2 U was given every 2 h starting from 15 min after administration of protamine until the end of operation in group H.TXA 20 mg/kg was injected intravenously at skin incision,followed by a continuous infusion of TXA at 10 mg· kg-1 · h-1 until the end of operation in group T.Hemocoagulase atrox and TXA were given as the method described in groups H and T.Venous blood samples were taken from the central vein before operation,at the end of operation,and 24 h after operation to determine the plasma D-Dimer concentration.The amount of blood loss,allogeneic red blood cells and plasma infused during operation,volume of drainage during 0-6 and 6-24 h after operation,total volume of drainage and volume of allogeneic blood transfused during operation were recorded.The deep vein thrombosis was recorded.Results Compared with group C,the amount of blood loss during operation was significantly decreased in groups T and HT,and the allogeneic red blood cells and plasma infused during operation,and volume of drainage during 0-6 and 6-24 h after operation,and total volume of drainage were significantly decreased in groups H,T and HT (P ＜ 0.05).Compared with groups H and T,the allogeneic red blood cells and plasma infused during operation,and volume of drainage during 0-6 and 6-24 h after operation,and total volume of drainage were significantly decreased in group HT (P ＜ 0.05).No deep vein thrombosis was observed in the 4 groups.Conclusion The combination of hemocoagulase artox for injection and TXA provides better blood-saving effect than either alone for the patients undergoing OPCABG without increasing the risk for thrombosis.

Objective To investigate the changes in trafficking of GluRl-containing AMPA (GluR1-AMPA) receptor and GluR2-AMPA receptor from cytoplasm to cell membrane in the spinal cord dorsal horn in a rat model of incisional pain.Methods Thirty-two adult male SD rats aged 6-8 weeks weighing 280-300 g were randomly divided into 2 groups:control group (group C,n =8) and incisional pain group (group Ⅰ,n =24).An 1 cm long incision was made in the plautar surface of right hindpaw according to Brennan et al.in group Ⅰ.Cumulative pain score (CPS) and paw-withdrawal threshold to yon Frey stimuli (PWT) were measured at 3 h and day 1 and 3 afar incision ( T1,2,3 ).The animals were sacrificed after pain behavior assessment.Their lumbar segments of the spinal cord (L3-6) were removed.The expression of GluR1 and GluR2 in cell membrane and cytoplasm in spinal cord dorsal horn was determined by Western blot analysis.The co-expression of Stargazing with GluR1 and GluR2 in the spinal cord dorsal horn was examined by co-immuno-precipitation.Results The CPS was increased and PWT decreased; the GluR1 expression in cytoplasm was decreased while the expression of GluR1 in cell membrane and the co-expression of Stargazing with GluR1 were up-regulated in group Ⅰ as compared with group C.There was no significant change in the expression of GluR2 in cytoplasm and cell membrane and the co-expression of Stargazing with GluR2 in group Ⅰ as compared with group C.Conclusion GluR1-AMPA receptor transfers from cytoplasm to cell membrane but GluR2-AMPA receptor does not in rats with incisional pain.

Objective To investigate the time-dependent changes in glutamate (Glu) and 7-aminobutyric acid ( GABA) release in the rostral ventromedial medulla in a rat model of incisional pain. Methods Healthy male SD rats weighing 250-300 g were used in this study. Twelve rats in which microdialysis cannulae were implanted in the right rostral ventromedial medulla without neurological deficits were randomly divided into 2 groups ( n = 6 each): group A control and group B incisional pain. In group B an 1 cm long incision was made in the plantar surface of right hindpaw under 1.2% isoflurane anesthesia which was maintained for 5 min. Samples of dialysate were collected before incision (T_0 baseline) and at 3 h, 1 d, 2 d and 3 d after incision was made (T_(1-4)) in both groups for determination of Clu and GABA concentrations (by HPLC). Results In group B Glu and GABA concentrations in the dialysate were significantly increased at 1 d (T_2) and 3 h-3 d (T_(1-4)) respectively as compared with the baseline value at T_0 and were significantly higher than those in group A (control group). Conclusion Incisional pain increases the release of Glu and GABA in the rostral ventromedial medulla which might influence the function of descending pain modulation pathway.