1.Study on impact mechanism of four different anesthetics on middle cerebral artery blood flow velocity
Chongqing Medicine 2015;(14):1885-1887
Objective To compare the impacts of four different intravenous anesthetic agents on middle cerebral artery blood flow velocity(V‐MCA) during the anesthesia induction period .Methods Totally 80 cases were randomly divided into four groups (n=20) ,maintenance drugs of anesthesia were propofol 2 .00 mg/kg ,etomidate 0 .30 mg/kg ,midazolam 0 .15 mg/kg and dezocine 0 .20 mg/kg respectively ,the bispectral index (BIS) value was dropping to below 50 ,the endotracheal intubation and mechanical ventilation were performed .The transcranial Doppler (TCD) monitoring was adopted to monitor and record middle cerebral artery mean flow velocity (Vm‐MCA) ,mean arterial pressure (MAP) ,heart rate (HR) ,systolic blood pressure (SBP) ,diastolic blood pressure (DBP) in the four groups before induction after entering operation room (T0 ) ,at1 min before intubation (T1 ) ,immediate intubation (T2 ) ,at 1 min after intubation (T3 ) ,3 min after intubation (T4 ) ,5 min after intubation (T5 ) .Results Except for the midazolam group ,Vm‐MCA at T1 in the other three groups were significantly lower that that in the T0 group (P< 0 .05);Vm‐MCA ,SBP ,DBP after intubation in the midazolam group and the etomidate group were significantly increased compared with the basic values ,while the difference between the propofol group and the dezocine group had no statistical significance (P>0 .05) .Con‐clusion midazolam and etomidate are weaker than propofol and dezocine in the aspect of inhibiting the middle cerebral arterial blood flow fluctuations caused by intubation .
2.Impact of lidocaine on the inhibitory effect of propofol on P2X_7-gated currents
Chinese Pharmacological Bulletin 2003;0(07):-
Aim To investigate the effects of propofol and lidocaine on P2X7-gated currents and the interaction of both drugs.Methods RAW2647 macrophages were cultured,whole-cell patch clamp technique was used to record the P2X7-gated currents induced by ATP with two times EC50 level under 1~100 ?mol?L-1 propofol or 10~1 000 ?mol?L-1 lidocaine. Then,propofol of IC50 level and lidocaine with 10~1 000 ?mol?L-1 were administered,and the P2X7-gated currents were recorded.Results Propofol and lidocaine could inhibit P2X7-gated currents in a concentration-dependent manner,and the IC50 level was (36.5?5.3) ?mol?L-1 and (223?34) ?mol?L-1,respectively. Lidocaine with high concentration (300 ?mol?L-1,1 000 ?mol?L-1) following the administration of propofol of EC50 level could increase the P2X7-gated currents(P
3.The dynamic change of ATPase activities in rat brain with propofol anesthesia
Jing ZHANG ; Jinrong ZHANG ; Tijun DAI ;
Chinese Pharmacological Bulletin 1986;0(06):-
AIM To investigate the effects of propofol on Na +, K + ATPase and Ca 2+ ATPase activities in rat brain. METHODS Forty rats were divided randomly into five groups. The animals were administered intraperitoneally (ip) propofol 100 mg?kg -1 or equal volume of normal saline (control group) respectively. These rats were immediately decapitated before (induction group) and after (anesthesia group) the disappearance of righting reflex, and when righting reflex appeared again (recovery group), and rats were completely conscious (awake group). Brain tissues were dissected on ice, then homogenized and centrifuged. Na +, K + ATPase and Ca 2+ ATPase activities were estimated by spectrophotometry. RESULTS Propofol 100 mg?kg -1 ip significantly inhibited Na +, K + ATPase and Ca 2+ ATPase activities of cortex, hippocampus and brain stem as compared with that of normal saline group ( P
4.Effecet of intrathecal injection of 6-OHDA or ?_1-adrenoceptor antagonist on the spinal analgesia of ketamine
Zhijun GE ; Tijun DAI ; Yinming ZENG ;
Chinese Pharmacological Bulletin 2003;0(08):-
Aim To investigate the relationship between spinal cord noradrenergic neurons ? 1 adrenoceptors and the spinal analgesia of ketamine. Methods Kunming mice were used. Analgesia tests were investigated with warm water tail flick test. The effects of intrathecal injection (ith) of ketamine (50,100,200 ?g)on tail flick latency of animals were observed. And the effect of pretreatment with intrathecal 6 hydrodoapa(6 OHDA, 6?g ) and ? 1 adrenoceptor antagonist prazosin (5, 15 ?g) or terazosin (5, 15 ?g) , respectively on the spinal analgesia of ketamine (100 ?g,ith) was studied. Results Dose dependent analgesia was observed following ith ketamine (100,200 ?g, P
5.An experimental study on the central effects of procaine.
Chinese Journal of Anesthesiology 1994;0(04):-
The analgesic, sedative and convulsive effects of procaine were determined by animal experiments. The analgesic ED50 of procain were 21.7mg/kg or 52.8ug/ each (iv or icv, hot plate) and 29.2mg/kg or 52.2ug/ each (iv or icv,electral stimulation) in mice.Procaine In subthreshold dose had additive hypnotic effect of phenobarbital in mice and rabbits, but could not de crease spontaneous activity in mice.The convulsive ED50 of procaine were 13.5mg/kg (iv) or 2.4mg/each (icv) in rabbits.There was no influence on the righting reflex in all the experiment animals when iv or icv procaine was given alone.These results suggest that the analgesic and sedative effects of procaine are weak, but may be potentiated when administered concomitantly With other potent drugs.
6.Effects of sodium oxybate on pharmacodynamics of ketamine in animals
Chinese Journal of Anesthesiology 1996;0(08):-
The interaction between sodium oxybate and ketamine were studied in conscious animals. Sodium oxybate increased the LD_(50) of ketamine, increased the incidence of sleep caused by ke tamine and prolonged the sleep duration and potentiated analgesic action of ketamine. Sodium Oxybate didn't effect the respiratory and circulatory function in rabbits. The results showed sodium oxybate po tentiated the anesthetic action of ketamine and reduced the side effect of ketamine. So It is suggested that sodium oxybate has the anesthetic synergism with ketamine in animals.
7.Effects of intrathecal injection of NMDA on the analgesia of inhalation anesthetics
Lihua HANG ; Tijun DAI ; Yinming ZENG
Chinese Pharmacological Bulletin 2003;0(09):-
0.05);in contrast, intrathecal NMDA 2.5,5,10 ng could significantly and dose dependently decrease the HPPT(P
8.GABA_A receptor mediated inhibitory effect of thiopental sodium on glutamate release from prefrontal cortical synaptosomes in rats
Hongliang LIU ; Tijun DAI ; Shanglong YAO
Chinese Journal of Anesthesiology 1994;0(05):-
Objective To investigate the effect of thiopental sodium (TPS) on spontaneous and KCl-evoked glutamate release from prefrontal cortical synaptosomes in rats and the effect of bicuculline on this effect ofTPS.Methods SD rats of both sexes (200-250 g) were decapitated and brains were removed. The prefrontalcortex was dissected and added to ice-cold sucrose solution and homogenized. The homogenate was centrifuged at1000 g at 0℃-4℃ for 5 min. The supernatant was again centrifuged at 12 000 g for 20 min. The sediment wascrude synaptosomes, which was added to artificial cerebro-spinal fluid (ACSF). The crude synaptosomes weredivided into 5 groups (n = 8): control group and 4 TPS groups. In control group no TPS was added while in TPSgroups different concentrations of TPS was added and the final concentration of TPS was 10, 30, 100, 300?mol?L~(-1) respectively. The synaptosomes were then placed with or without KCl in water bath at 37℃ for 15 min. Thespontaneous or KCl-evoked glutamate release was measured using high-performance liquid chromatograph (HPLC).In another set of experiment bicuculline 0. 1 mmol?L~(-1) was added to ACSF in each group before 15 min water bathto see if it could antogonize the effect of TPS on glutamate release. Results TPS 30, 100 and 300 ?mol?L~(-1)could significantly inhibit the spontaneous or KCl-evoked glutamate release compared with control group (P0.05). Bicuculline 0. 1 mmol?L~(-1) had no effect on the glutamate release in control group but could antagonize the inhibitory effect of TPS on glutamate release. Afteraddition of bicucculline the glutamate released in control group was not significantly different from that in the TPSgroups.Conclusion TPS sodium can inhibit the spontaneous or KCl-evoked glutamate release from prefrontalcortical synaptosomes in a concentration-dependent manner. The inhibitory effect is mediated by GABA_A receptors.
9.Effects of propofol on P2X7 receptor activition and IL-1β production induced by endotoxin in murine RAW264.7 macrophages
Hongliang LIU ; Yuhua LIU ; Tijun DAI
Chinese Journal of Anesthesiology 2009;29(9):842-845
Objective To investigate the effects of propofol on P2X7 receptor activition and IL-1β production induced by endotoxin in murine RAW264.7 macrophages. Methods RAW264.7 macruphages were treated with LPS (1 μg/ml) for 4 h to induce the production and release of IL-1β, and pretreated with BBG (specific P2X7 receptor antagonist) 1 μmol/L or propofol 1-100 μmol/L for 20 min before LPS stimulation, and IL-1β release was measured using ELISA kit. Whole-cell patch clamp technique was used to record the P2X7-gated currents induced by 1 mmol/L ATP, the cells were exposed to propofol with 1-1 000 -μmol/L for 4 min, and the IC_(50) level of propofol was achieved. Western blot technique was used to measure the production of pro-lL-1β protein and IL-1β protein intracellularly after LPS treatment for 4 h under different concentrations of propofol. Results IL-1β was released from RAW264.7 macrophages after LPS stimulation, which was decreased by propofol, and the IC_(50) level of propefol was (24±3) μmol/L. P2XT-gated currents were inhibited by propofol, and the IC_(50) level was (33±5) μmol/L. Pro-IL-1β protein intracellularly was up-regulated after LPS stimulation, and propofol with 3-100 μmol/L decreased the up-regulation of pro-IL-1β intracellularly induced by LPS. Conclusion Propefol could inhibit IL-1β release from RAW264.7 macrophages treated by LPS, which is mediated by inhibiting P2X7 receptor activition and decreasing the production of pro-IL-1β intracellularly.
10.Changes in nitric oxide synthase (NOS) positive neurons in limbic system induced by isoflurane or enflurane in rats
Jing LU ; Tijun DAI ; Yinming ZENG
Chinese Journal of Anesthesiology 1995;0(10):-
0.05) compared to control group. Conclusion Induction of anesthesia with isoflurane or enflurane decreases the number of NOS positive neurons in the 6 nuclei in limbic system. The changes in NOS positive neurons in limbic system may be involved in the mechanism of isoflurane and enflurane anesthesia.