Objective To investigate the effects of isoflurane on cyclic adenosine monophosphate (cAMP ) content of brain in the rats. Methods Fourty SD rats were allocated randomly to 5 groups: no administration(control group,n=8), inhalation of 1.4% isoflurane until losing of righting reflex(loss of righting reflex group,n=8), inhalation of 1.4% isoflurane lasting 30 min(anesthesia group,n=8) ,righting reflex recovery after cessation of 30-min inhalation of 1.4% isoflurane (recoveryⅠ group,n=8) and 30 min after cessation of 30-min inhalation of 1.4% isoflurane (recovery Ⅱ group,n=8). The rats of each group were decapitated at the end of procedures to measure the cAMP content of brain tissue with competitive protein binding assay.Results As compared with that in control group,the cerebrocortical cAMP content only in anesthesia group significantly increased by 49% (P

Objective To determine the effects of isoflurane on the amino acid neurotransmitter contents in rat cerebral cortex, hippocampus and spinal cord. Methods Sixteen male SD rats weighting 220-280g were randomly divided into two groups: isoflurane group (A) and control group (B). Animals in group A were killed after 30min inhalation of 1.3% isoflurane and cerebral cortex, hippocampus and spinal cord were removed immediately for determination of glutamic acid (Glu), aspartic acid (ASP), glutamine (Gln), GABA and glycine (Gly) levels by high-performance liquid chromatography (HPLC), whereas in group B O2 was inhaled instead of isoflurane. Results As compared with control group, Asp and Glu levels in cerebral cortex and hippocampus decreased markedly while Gly level increased significantly in hippocampus and spinal cord in isoflurane group. Conclusions The inhibition of excitatory amino acid synapse transmission and augmentation of inhibitory amino acid synapse transmission may be involved in the mechanism of isoflurane anesthesia.

B-7601.

Constant infusion, exponentially declining infusion and program infusion of theophlline were administered to rabbits byadopting the rabbit population pharmacokinetic parameters in this laboratory, and the plasma concentrations of the drug was measured by ul- traviolet spectrophotometry. The results showed that the plasma drug concentrations following exponentially declining infusion and program infusion attained the desired steady-state level at only 30 min, though the T1/2?= 6. 08h, The median absolute value of performance error in pro-gram infusion and exponentially declining infusion was 7. 8% and 14% respectively.

Objective To investigate the effects of GABAA receptor agonist-muscimol and GABAA receptor antagonist-bicuculline on brain cyclic adenosine monophosphate (cAMP) content in rats undergoing isoflurane anesthesia. Methods Forty-eight SD rats of both-sexes weighing 200-250g were randomly divided into 6 groups: group I received intraperitoneal (ip) normal saline (NS) 10ml.kg-1 (control group); group II in which animals inhaled 1.4% isoflurane for 30 min, 30 min after NS ip (isoflurane group);group IE in which animals inhaled 1.4% isoflurane for 30 min, 30 min after muscimol Img-kg ip (muscimol + isoflurane group); group IV in which animals inhaled 1.4% isoflurane for 30min, 30 min right after bicuculline 8 mg.kg-1 ip (bicuculline + isoflurane group); group V received muscimol lmg. kg-1 (muscimol group); group VI received bicuculline 8mg.kg (bicuculline group). The animals were decapitated 1h after 30min isoflurane inhalation or intraperitoneal NS or muscimol or 5min after bicuculline ip (rats developed convulsion within 7 min after bicuculline ip) . Brain was removed immediately for determination of cAMP content of cortex or brain stem. Loss of righting reflex was taken as sign of anesthesia. Brain cAMP content was measured by competitive protein binding assay. Results Muscimol shortened the time of loss of righting reflex induced by isoflurane (P

AIM To investigate the protective effect of sodium gamma-hydroxybutyrate (?-OH) against cerebral ischemia-reperfusion injury in gerbils and the neuroprotective mechanism of ?-OH. METHODS The occlusion of bilateral carotid arteries of gerbil was used to make the cerebral ischemia-reperfusion models. Different doses of ?-OH were administered intraperitoneally 40 min prior to the onset of ischemia. After 10 min ischemia and 1 h reperfusion, bilateral hippocampus, cortex and striatum were taken out to measure ATPase, SOD and MDA. RESULTS The contents of MDA markedly elevated while Na +,K +-ATPase, Ca 2+ -ATPase and SOD activities decreased in hippocampus, cortex and striatum 1 h after ischemia-reperfusion. ?-OH administered prior to ischemia can partly reverse the elevation of MDA contents and the reduction of SOD activities. ?-OH given after ischemia can still provide partly protective effect. CONCLUSION ?-OH provides significant protective effect against cerebral ischemia-reperfusion injury by protecting ATPase and SOD activities, deleting free radicals and reducing the lipid peroxidation.

AIM:?To?investigate?if?alfentanil?protects?the?isolated?rat?heart?against?myocardial?reperfusion?injury?and?if?the?mechanism?of?this?protection?is?mediated?via?opioid?receptors?and?NO-dependent?pathways. METHODS: Langendorff rat hearts were perfused at constant pressure with Kreb-Henseleit(K-H) buffer for 20 min?and?then?were?perfused?with?test?solution:?K-H?buffer?or?K-H?buffer?containing?alfentanil? 50 ?g?L -1,?alfentanil? 100 ?g?L -1, naloxone 200 ?g?L -1, alfentanil 100 ?g?L -1+naloxone 200 ?g?L -1, L-NAME 100 ?mol?L -1 and alfentanil 100 ?g?L -1+L-NAME 100 ?mol?L -1. After 10 min of this, the hearts were subjected to 25 min normothermic( 37 ℃) global ischemia followed by 30 min reperfusion with the same test solution as before. To evaluate myocardial function, LVEDP, LVDP, ?dp/dt max, HR and CF were measured at the 20th, 25 and 30th minute of perfusion and the 1st, 3rd, 5th, 10th, 20th and 30th minute of reperfusion. After experiment, the NOS and ATP content of myocardium were assessed. RESULTS: Before ischemia, alfentanil 100 ?g?L -1 decreased the HR at the 30th minute compared with the 20th minute(P

OBJECTIVE To investigate the influence of short hairpin RNA targeting human telomerase reverse transcriptase(hTERT)on inhibition of telomerase activity and on expression of protein c-myc in nasopharyngeal carcinoma cells. METHODS Plasmid shRNA1 containing fluorescein gene and hTERT cDNA sequences were synthesized. Cells were transfected with plasmid shRNA1. The cell viability was examined using the MTT assay. The activity of telomerase was tested by polymerase chain reaction telomeric repeat amplification protocol- enzyme-linked immunosorbent assay (PCR-TRAP- ELISA),protein c-myc expression was tested by western blot. RESULTS It was observed that treatment with pshRNA1 in the presence of a valid transfection reagent could significantly reduce telomerase activity and the expression of protein of c-myc. CONCLUSION Inhibition of telomerase activity or expression of hTERT mRNA in nasopharyngeal carcinoma cells could inhibit cells proliferation and reduce the expression of protein of c-myc.

BACKGROUND:Tetramethylpyrazine (TMP) can inhibit the expression of vascular endothelial growth factor (VEGF), but it is uncertain that TMP inhibit the growth and proliferation of HL-60 leukemic cells induced by VEGF.OBJECTIVE:To observe the effect of TMP on the proliferation of HL-60 leukemic cells induced by VEGF.DESIGN:Repetitive measurement and observation.SETTING:School of Medicine, Wuhan University of Science and Technology.MATERIALS:The experiment was carried out in the Molecular Biology Laboratory Center, School of Medicine, Wuhan University of Science and Technology from March to June in 2007. Human leukemic cell line HL-60 cells were purchased from Shanghai Institute of Cell Biology. TMP hydrochloride injection was produced by Wuxi Seventh Pharmaceutical Products Limited (Lot number:011014), protamine sulfate injection was produced by Shanghai First Biochemical Pharmaceuticals (Batch number:010302), and immunohistochemistry kit was purchased from Boster company.METHODS:①Human leukemic cell line HL-60 cells at log phase were used for the experiments. Cells were treated with 100 μg/L VEGF, and then TMP at final concentrations of 1.5, 15, 150 mg/L was added into culture medium. While the cells in medium without TMP were taken as blank control group, and the cells in medium with 20 mg/L protamine as positive control group. Meanwhile cells without treatment of VEGF were served as VEGF control group. After cells were incubated for 48 hours, the growth inhibiting rate of HL-60 cells was detected by MTT assay.②After HL-60 cells were treated with TMP at the final concentrations of 1.5, 15, 150 mg/L for 24 hours, the protein expression of VEGF in HL-60 cells was examined by SP immunohistochemistry.MAIN OUTCOME MEASURES:①Growth inhibiting rate of HL-60 cells.②Protein expression of VEGF.RESULTS:①Growth inhibiting rate of HL-60 cells:After HL-60 cells induced by VEGF were treated with 15 and 150 mg/L TMP, the absorbance value was significantly lower than that in VEGF control group (P < 0.05).②Protein expression of VEGF:After HL-60 cells were treated with TMP for 24 hours, the protein expression of VEGF was down-regulated with increasing TMP concentration in a dependent manner. Significant differences were observed in the protein expression of VEGF between cells treated by TMP and the controls (P < 0.01).CONCLUSION:shRNA, by targeting hTERT mRNA, has no noticeable influence on growth and proliferation of hMSCs, and might be safe for the somatic cells which are normal but do not express hTERT.