Objective To investigate the inhibitant effects of parecoxib, a cyclooxygenase-2 (COX-2) inhibitor, in acute fentanyl induced hyperalgesia in rats. Methods (1) Thirty SD rats (n=6 for each group) were subcutaneously injected with fentanyl (40 μg/kg × 4 times with a 15 min-interval) or saline to establish acute fentanyl induced hyperalgesia model, andparecoxib (5, 10 mg/kg) was administrated intraperitoneally in parecoxib group. Mechanical nociceptive thresholds were measured by the tail pressure test every hour during 1~4 hours and once a day during 1~5 days. (2) 24 SD rats (n = 6 foreach group) were subcutaneously injected with fentanyl as above described and randomly administrated intraperitoneally with parecoxib in 10 mg/kg in 15 min before and at the 4th hour and the 1st day after fentanyl injection except rats in the control group, mechanical nociceptive thresholds were measured by the tail pressure test at time points as above described. Results (1)Acute high dose fentanyl injection induced mechanical hyperalgesia and parecoxib (at 5 or 10 mg/kg)inhibited fentanyl induced hyperalgesia in rats. (2)Parecoxib inhibited fentanyl induced hyperalgesia at 15 min before and at the 4th hour after, but not on the 1st day after fentanyl injection. Conclusions This study provides the first evidence that subanalgesia doses of parecoxib had inhibitory effects on acute fentanyl induced hyperalgesia in time-dependent manners in rats.

Objective To investigate the safety of autologous blood component transfusion during cesarean section in patients with Rh (D)-negative blood group.Methods Thirty ASA Ⅰ or Ⅱ patients of Rh (D)-negative blood group, aged 20-35 yr, weighing 50-80 kg, undergoing elective cesarean section, were enrolled in this study.After lactated Ringer' s solution 7 ml/kg was infused, blood was obtained from radial artery at a rate of 60-80ml/min, and blood volume was maintained by simultaneous infusion of 6% hydroxyethyl starch 130/0.4 at the same rate. The collected blood was subjected to two cycles of autologous blood component separation. Blood collecting during each cycle was stopped 15 s after red blood cells were separated. The autologous blood was infused when the blood loss≥20% of blood volume. The autologous blood was infused after suture of the uterus when the blood loss < 20% of blood volume. The parameters of maternal vital signs and fetal heart rate were monitored. Hypotension and tachycardia were recorded during autologous blood collecting. SpO2 was monitored routinely. Venous blood samples were taken before blood collecting (baseline), at the end of blood collecting, before autologous blood transfusion, 24 h after operation for determination of Hb, Hct, Plt, PT, APTT, INR and Fib. Umbilical arterial blood samples were obtained after delivery for blood gas analysis. Apgar score was recorded at 1 and 5 min after birth. Blood loss and allogeneic blood transfusion were also recorded. Results No hypotension and tachycardia occurred during the process of blood collecting and the fetal heart rate was within the normal range. Compared with the baseline value, there were no significant differences in SpO2 , Hb, Hct, Plt, PT, APTT, INR and FIB value at the other time points. The pH value and concentrations of base excess and lactate were within the normal range.The Apgar score was (9.0 ±0.8) and (9.2 ± 0.8) at 1 and 5 min after birth respectively. The blood loss during operation was (405 ± 28) ml and no patients received homologous blood transfusion. Conclusion The safety of autologous blood component transfusion is good during cesarean section in Rh (D)-negative blood group patients.

Objective]To investigate the change of spinal pro?inflammatory cytokines in a rat model of fentanyl induced acute hyperalgesia.[Methods]64 male SD rats were divided into 2 groups(n=32),fentanyl group and NS group. The rats were subcutaneously injected with fentanyl (60 μg/kg) or normal saline (1.2 mL/kg) 4 times with 15?minute intervals. Mechanical nociceptive thresholds and thermal nociceptive latency were measured via the tail pressure test(Tail flick thresholds,TFT) and paw withdrawal test(Paw withdrawal latency,PWL)on the day before,at 1,2,3,and 4 hour and on 1~5 day after injection. 4 rats were killed concomitantly and the lumber spinal cord were harvested to analysis the expression of NF-κB,PGE2,TNF-α,IL-1β,and IL-6.[Results]There were no significant changes of TFT,PWL and the expression of spinal inflammatory cytokines such as NF-κB, PGE2,IL-1β,and TNF-αcompared to baseline of rats treated with normal saline. The value of TFT ,PWL in fentanyl group raised to the highest(above the baseline)at the 1st hour after fentanyl injections and decreased thereafter,reached the lowest at the 1st day, raised increasinglyand up to baseline on the 3 day after injection. NF-κB,PGE2,IL-1β,and TNF-αincreased at the 4th hour,on 1 and 2 day and IL-6 increased at the 4 hour and onthe 1 day after fentanyl injections.[Conclusion]Subcutaneously injection of fentanyl induced significant mechanical and thermal hyperalgesia and increased spinal pro?inflammatory cytokines parallelly , indicated that fentanyl induced acute hyperalgesia is associated with spinal inflammatory reaction in rats.

OBJECTIVE:To study the analgesic effect and mechanism of Gutongtie paste on model rats with formaldehyde-in-duced pain. METHODS:60 SD rats were randomly divided into blank group,model group,Gutongtie paste low-dose,medi-um-dose,high-dose groups(0.594,1.188. 2.376 g/paste,containing crude drug 0.48,0.96,1.92 g)and prednisone acetate group (ig,0.0054 g/kg,external bonding matrix). Model rats with pain was induced by formaldehyde method and immediately adminis-trated after modeling. Electronic tenderness instrument was adopted to determine the pain threshold of rats'ankle joint after adminis-tration of 1,2,3,4,6 h. After 6 h,blood sample 0.3 mL was taken from abdominal aorta then rats were sacrificed. Enzyme linked immunosorbent assay (ELISA) was conducted to determine the β-endorphin (β-EP),prostaglandin E2 (PGE2) contents;spectrophotometry was used to determine nitric oxide(NO)content in rats'serum and inflammatory tissue;and radioimmunoassay was adopted to detect the substance P content in rats'serum,inflammatory tissue and brain tissue. RESULTS:Compared with be-fore modeling,pain thresholds in model group at each period were significantly decreased (P<0.05 or P<0.01). Compared with blank group,PGE2,NO of rats,substance P content in inflammatory tissue and brain tissue in model group were significantly in-creased (P<0.05 or P<0.01). Compared with model group,pain thresholds in Gutongtie paste groups at corresponding time points were increased,PGE2 and substance P contents in inflammatory tissue and brain tissue were decreased (P<0.05 or P<0.01);β-EP and NO contents in serum in Gutongtie paste medium-dose,high-dose groups(P<0.05 or P<0.01),NO contents in serum in Gutongtie paste high-dose group were decreased(P<0.05). CONCLUSIONS:Gutongtie paste has a certain analgesic and anti-inflammatory effect,and the mechanism may be related to reducing PGE2, NO, substance P contents, increasing β-EP content.