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Objective:To evaluate the effect of sleep fragmentation on postoperative cognitive dysfunction (POCD) and hippocampal glutaminergic metabolism in aged mice anesthetized with isoflurane.Methods:Forty healthy SPF-grade male C57BL/6J mice, aged 18 months, weighing 20-30 g, were divided into 4 groups ( n= 10 each) by the random number table method: normal control group (group C), sleep fragmentation group (group SF), isoflurane anesthesia/surgery group (group I/S), and sleep fragmentation plus isoflurane anesthesia/surgery group (group SF+ I/S). Group C did not received any treatment. Group SF received sleep fragmentation for 24 h. The right carotid artery exposure was performed under isoflurane anesthesia in group I/S. Group SF+ I/S received isoflurane anesthesia/right carotid artery exposure at 24 h after sleep fragmentation. The metabolic levels of glutamate (Glu), glutamine (Gln), Glu/Gln complex (Glx), and N-acetylaspartate (NAA) and their ratio to creatine (Cr) were measured by in vivo 9.4T hydrogen proton magnetic resonance spectroscopy at 2 h after anaesthesia. Y maze and Morris water maze tests were used to evaluate the cognitive function at 1-7 days after surgery. The mice were sacrificed after the behavioral testing, brain tissues were immediately obtained, and the number of Nissl bodies and density of dendritic spines in the hippocampal CA1 region were measured by Nissl staining and Golgi staining, respectively. Results:Compared with group C, the percentage of exploration time and shuttle times at the novel arm were significantly decreased, the number of crossing the original platform was decreased, the time of stay at the target quadrant was shortened, the ratios of Glu/Cr, Gln/Cr and Glx/Cr in the hippocampal CA1 region were increased, and the ratio of NAA/Cr was decreased, and the number of Nissl bodies and density of dendritic spines were decreased in SF, I/S and SF+ I/S groups ( P<0.05). Compared with group SF and group I/S, the percentage of exploration time and shuttle times at the novel arm were significantly decreased, the number of crossing the original platform was decreased, the time of stay at the target quadrant was shortened, the ratios of Glu/Cr and Glx/Cr in hippocampal CA1 region was increased, the ratio of NAA/Cr was decreased, and the number of Nissl bodies and density of dendritic spines were decreased in group SF+ I/S ( P<0.05). Conclusions:Sleep fragmentation exacerbates POCD in aged mice anesthetized with isoflurane, and the mechanism is related to nerve injury induced by abnormality in hippocampal glutaminergic metabolism excitability.
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Objective:To evaluate the effect of gender on anesthetic potency of ciprofol for gastroscopy when combined with fentanyl.Methods:American Society of Anesthesiologists Physical Status classification Ⅰ or Ⅱ patients, aged 18-50 yr, with body mass index of 18-25 kg/m 2, undergoing elective gastroscopy with intravenous anesthesia, were divided into 2 groups according to gender: male group (M group) and female group (F group). After fentanyl 1.5 μg/kg was intravenously injected, ciprofol was given by the Dixon′s up-and-down method, with the initial dose of 0.4 mg/kg followed by dose increment/decrement of 0.04 mg/kg. The ED 50 and 95% confidence interval of ciprofol for gastroscopy anesthesia were calculated by the probit regression analysis. Results:The ED 50 (95% confidence interval) of ciprofol for gastroscopy was 0.33 (0.32-0.34) mg/kg in F group and 0.27 (0.26-0.28) mg/kg in M patients when combined with fentanyl 1.5 μg/kg. There was no significant difference between the two groups ( P>0.05). Conclusions:There is no significant gender difference in the anesthetic potency of ciprofol for gastroscopy (ED 50: female 0.33 mg/kg, male 0.27 mg/kg) when combined with fentanyl (1.5 μg/kg).
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Hepatocellular carcinoma (HCC) is a malignant tumor with a high incidence in China. Bone is a common extra hepatic metastasis site of HCC. Bone metastasis of HCC not only has a serious impact on the quality of life of patients, but also shortens their survival time. However, the pathogenesis of bone metastasis of HCC remains unclear. This review summarizes the clinical features, pathogenesis, prognostic factors, diagnosis and treatment progress and other aspects of bone metastasis of HCC, in order to provide new ideas for the clinical diagnosis and treatment.
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Objective:To evaluate the relationship between CCL21 and triggering receptor expressed on myeloid cells 2 (TREM2)/DNAX-activating protein of 12 kDa (DAP12) signaling pathways in the spinal dorsal horn in remifentanil-induced hyperalgesia in mice with incisional pain.Methods:Thirty-two SPF healthy male C57BL/6J mice, weighing 18-22 g, aged 8-10 weeks, were divided into 4 groups ( n=8 each) using a random number table method: control group (group C), CCL21 neutralizing antibody group (group anti-CCL21), remifentanil + incisional pain group (group R+ I), and CCL21 neutralizing antibody + remifentanil + incisional pain group (group anti-CCL21+ R+ I).A CCL21 neutralizing antibody 0.3 μg (diluted to 10 μl in normal saline) was intrathecally injected in anti-CCL21 and anti-CCL21+ R+ I groups twice a day.Normal saline 10 μl was intrathecally injected at the same time point twice a day in C and R+ I groups.Fifteen min after intrathecal injection, normal saline 0.1 ml was injected via the caudal vein for 4 consecutive times at an interval of 15 min in C and anti-CCL21 groups, and remifentanil 10 μg/kg (diluted to 0.1 ml in normal saline) was injected via the caudal vein for 4 consecutive times at an interval of 15 min in R+ I and anti-CCL21+ R+ I groups.The tail-flick latency (TFL) and mechanical paw withdrawal threshold (MWT) were measured at 24 h before remifentanil or normal saline injection (T 0) and 3, 6, 24 and 48 h after stopping injection of remifentanil or normal saline (T 1-4).The mice were sacrificed after the last measurement of pain threshold, and L 4-6 segments of the spinal cord were removed for determination of the expression of TREM2 and DAP12 protein and mRNA (by Western blot or quantitative real-time polymerase chain reaction). Results:Compared with group C, TFL was significantly shortened and MWT was decreased at T 1-4, and the expression of TREM2 and DAP12 protein and mRNA was up-regulated in group R+ I and R+ I+ anti-CCL21 ( P<0.05), and no significant change was found in the parameters mentioned above in group anti-CCL21 ( P>0.05).Compared with group R+ I, TFL was significantly prolonged and MWT was increased at T 1-4, and the expression of TREM2 and DAP12 protein and mRNA was down-regulated in group anti-CCL21+ R+ I ( P<0.05). Conclusions:CCL21 is involved in remifentanil-induced hyperalgesia by activating TREM2/DAP12 signaling pathways in the spinal dorsal horn of mice with incisional pain.
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Remifentanil is widely used to control intraoperative pain. However, its analgesic effect is limited by the generation of postoperative hyperalgesia. In this study, we investigated whether the impairment of transmembrane protein 16C (TMEM16C)/Slack is required for α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic receptor (AMPAR) activation in remifentanil-induced postoperative hyperalgesia. Remifentanil anesthesia reduced the paw withdrawal threshold from 2 h to 48 h postoperatively, with a decrease in the expression of TMEM16C and Slack in the dorsal root ganglia (DRG) and spinal cord. Knockdown of TMEM16C in the DRG reduced the expression of Slack and elevated the basal peripheral sensitivity and AMPAR expression and function. Overexpression of TMEM16C in the DRG impaired remifentanil-induced ERK1/2 phosphorylation and behavioral hyperalgesia. AMPAR-mediated current and neuronal excitability were downregulated by TMEM16C overexpression in the spinal cord. Taken together, these findings suggest that TMEM16C/Slack regulation of excitatory synaptic plasticity via GluA1-containing AMPARs is critical in the pathogenesis of remifentanil-induced postoperative hyperalgesia in rats.
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Objective:To evaluate the relationship between the euchromatic histone-lysine N-methyltransferase (G9a) and sodium-dependent activation of potassium channel (Slack) in the dorsal root ganglia (DRG) of rats with neuropathic pain (NP).Methods:Forty-eight clean-grade healthy male Sprague-Dawley rats, aged 1 month, weighing 100-120 g, were divided into 4 groups ( n=12 each) by a random number table method: sham operation group (S group), vector plus sham operation group (VS group), vector plus NP group (VN group), and G9a CRISPR/Cas9 knockout plus NP group (GN group). Sham operation was performed at the age of 2 months in group S. In group VS, AAV5 1 μl was microinjected into L 4 and L 5 DRG at the age of 1 month, and sham operation was performed at the age of 2 months.In VN group and GN group, AAV5 and G9a CRISPR/Cas9 knockout plasmid 1 μl were microinjected into L 4 and L 5 DRG at the age of 1 month, and NP model was established by spinal nerve ligation (SNL) at the age of 2 months.Six rats in each group were selected to measure the mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) before microinjection (T 0), before SNL (T 1), and at 3, 5 and 7 days after SNL (T 2-4). The animals were sacrificed after the last behavioral testing, the DRGs of lumbar segment (L 4, 5) were removed for determination of the expression of G9a, dimethylation of histone H3 at lysine 9(H3K9me2) and Slack (by Western blot). At 7 days after establishing the model, 6 rats from each group were selected to culture the primary DRG neurons.The frequency and amplitude of Slack current in DRG neurons and miniature excitatory post-synaptic currents (mEPSCs) in the spinal dorsal horn were measured by whole-cell patch-clamp technique. Results:Compared with group S, the TWL was significantly shortened and the MWT was decreased at T 2-4, the expression of G9a and H3K9me2 in the spinal dorsal horn was up-regulated, the expression of Slack was down-regulated, the amplitude and frequency of Slack currents in DRG neurons were decreased, and the frequency of mEPSCs was increased in group VN ( P<0.05), and no significant change was found in the parameters mentioned above in group VS ( P>0.05). Compared with group VN, the TWL was significantly prolonged and the MWT was increased at T 2-4, the expression of G9a and H3K9me2 in the spinal dorsal horn was down-regulated, the expression of Slack was up-regulated, the amplitude and frequency of Slack currents in DRG neurons were increased, and the frequency of mEPSCs was decreased in group GN ( P<0.05). Conclusion:The mechanism of NP is related to up-regulating the expression of G9a in DRG, thus inhibiting the expression and opening of Slack channels in rats.
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Objective:To evaluate the effects of propofol on α-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) receptor expression in the hippocampus of neonatal rats.Methods:Eighty-four clean-grade healthy Sprague-Dawley rats of either sex, aged 7 days, weighing 14-18 g, were divided into 2 groups ( n=42 each) using a random number table method: control group (group C) and propofol group (group P). Propofol 30 mg/kg was intraperitoneally injected in group P, fat emulsion 3 mg/kg was intraperitoneally injected in group C, 1/2 of the initial dose was given at a 20 min interval, 3 times in total, for 3 consecutive days.The arterial blood samples were taken for blood gas analysis after administration on 1st day.The rats were sacrificed at 3, 7 and 28 days after the last administration of propofol, and the bilateral hippocampus was obtained for detection of the expression of AMPA receptors containing GluR1, GluR2 and GluR3 subunits in total and membrane protein (by Western blot), and the ratio of membrane protein to total protein (M/T) was calculated.The concentrations of free calcium ion were measured.The learning and memory ability was evaluated by Morris water maze test on 28 days after the last administration. Results:Compared with group C, the expression of AMPA receptor containing GluR1 subunit in total and membrane protein was significantly up-regulated, M/T was increased, the expression of AMPA receptor containing GluR2 subunit in total and membrane protein was down-regulated, and M/T was decreased at each time point ( P<0.05), no significant change was found in the expression of AMPA receptor containing GluR3 subunits ( P>0.05), the concentrations of free calcium ion in hippocampal cells were increased, and the escape latency was prolonged, the number of crossing the original platform was decreased, and the time of staying at the target quadrant was shortened at 2-4 days of training in group P ( P<0.05). Conclusion:The mechanism by which propofol reduces cognitive function is related to up-regulation of the expression of AMPA receptors containing GluR1 subunit in the hippocampus and down-regulation of the expression of AMPA receptors containing GluR2 subunits, which increases the concentration of free calcium ions in nerve cells of neonatal rats.
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Objective:To evaluate the role of secreted protein acidic and rich in cysteine like protein 1 (SPARCL1) in spinal dorsal horns in the development of remifentanil-induced hyperalgesia in mice with incisional pain.Methods:Forty-eight healthy male C57BL/6J mice, aged 8-10 weeks, weighing 18-22 g, were divided into 6 groups ( n=8 each) using a random number table method: control group (group C), incisional pain group (group I), remifentanil group (group R), incisional pain plus remifentanil group (group I+ R), incisional pain plus remifentanil plus negative control group (group I+ R+ N), and incisional pain plus remifentanil plus SPARCL1-siRNA group (group I+ R+ S). In I+ R+ N and I+ R+ S groups, 1×10 8 IFU/ml negative control siRNA and SPARCL1-siRNA 10 μl were intrathecally injected, respectively, once a day for 3 consecutive days.Normal saline 10 μl was intrathecally injected once a day for 3 consecutive days in C, I, R and I+ R groups.After transfection was stable, normal saline 0.1 ml was intravenously injected through the tail vein for 4 consecutive times at 15 min interval in C and I groups, and remifentanil 10 μg/kg (diluted to 0.1 ml in normal saline) was intravenously injected via the tail vein for 4 consecutive times at 15 min interval in R, I+ R, I+ R+ N and I+ R+ S groups.The incisional pain model was established after the first administration via the tail vein in R, I+ R, I+ R+ N and I+ R+ S groups.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 24 h before infusing normal saline or remifentanil (T 0) and 3, 6, 24 and 48 h after stopping infusion (T 1-4). Animals were sacrificed after measuring pain threshold at T 4, and L 4-6 segments of the spinal cord were removed for determination of the expression of SPARCL1 protein and mRNA by Western blot and quantitative real-time polymerase chain reaction, respectively. Results:Compared with group C, MWT was significantly decreased and TWL was shortened at T 1-4 in I+ R and I+ R+ N groups and at T 2-4 in I, R and I+ R+ S groups, and the expression of SPARCL1 protein and mRNA was significantly up-regulated in R, I+ R and I+ R+ C groups ( P<0.05 or 0.01). Compared with group I and group R, MWT was significantly decreased, TWL was shortened, and the expression of SPARCL1 protein and mRNA was up-regulated in group I+ R ( P<0.01). Compared with group I+ R, MWT was significantly increased and TWL was prolonged at T 1-4, and the expression of SPARCL1 protein and mRNA was down-regulated in group I+ R+ S ( P<0.05 or 0.01). Conclusion:Enhanced activity of SPARCL1 in the spinal dorsal horns is involved in the development of remifentanil-induced hyperalgesia in mice with incisional pain.
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Objective@#To evaluate the role of spinal COX-1 and COX-2 in remifentanil-induced hyperalgesia in mice with incisional pain.@*Methods@#Thirty-two male C57BL/6J mice, aged 8-10 weeks, weighing 20-25 g, were divided into 4 groups (n=8 each) using a random number table method: control group (group C), incisional pain plus remifentanil group (group IR), incisional pain plus remifentanil plus selective COX-1 inhibitor group (group IR+ SC560), and incisional pain plus remifentanil plus selective COX-2 inhibitor group (group IR+ SC236). In IR, IR+ SC560 and IR+ SC236 groups, normal saline 10 μl, SC560 25 μg and SC236 25 μg were intrathecally injected, respectively, 15 min later remifentanil 10 μg/kg was injected via the tail vein for 4 times at 15 min intervals.An incisional pain model was established after the first injection of remifentanil.The mechanical paw withdrawal threshold (MWT) was measured at 24 h before normal saline or remifentanil injection and 3, 6, 24 and 48 h after the last injection (T0-T4). The mice were sacrificed after the last measurement of pain threshold, and the L4-6 segments of the spinal cord were removed for determination of the expression of COX-1 and COX-2 (by Western blot) and expression of COX-1 and COX-2 mRNA (by quantitative real-time polymerase chain reaction).@*Results@#Compared with group C, the MWT was significantly decreased, and the expression of COX-2 protein and mRNA was up-regulated in IR, IR+ SC560 and IR+ SC236 groups (P<0.05). Compared with group IR, the MWT was significantly increased in IR+ SC560 and IR+ SC236 groups (P<0.05). There was no significant difference in the MWT at each time point between IR+ SC560 and IR+ SC236 (P>0.05) .There was no significant difference in the expression of COX-2 protein and mRNA among group IR, group IR+ SC560 and group IR+ SC236 (P>0.05). There was no significant difference in the expression of COX-1 protein and mRNA among the four groups (P>0.05).@*Conclusion@#Compared with COX-1, spinal COX-2 plays a major role in the pathophysiological mechanism of remifentanil-induced hyperalgesia in mice with incisional pain.
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Objective To evaluate the role of neuroligin 1 (NL-1) in trafficking of GluR1-containing AMPA receptor to cell membrane in spinal cord dorsal horns during remifentanil-induced hyperalgesia in mice with incisional pain.Methods Forty SPF healthy male C57BL/6J mice,aged 8-10 weeks,weighing 18-22 g,were divided into 5 groups (n=8 each) using a random number table method:control group (group C),NL1-shRNA plasmid group (group NL),incisional pain plus remifentanil group (group I+R),incisional pain plus remifentanil plus blank vector group (group I+R+B),and incisional pain plus remifentanil plus NL-1-shRNA plasmid group (group I+R+NL).Negative lentivirus was intrathecally injected in group I+R+B.In NL and I+R+NL groups,10 μl NL-1-shRNA lentivirus at 1×10s IFU/ml was intrathecally injected once a day for 3 consecutive days.Normal saline 10 μl was intrathecally injected at the same time point in C and I+R groups.After transfection was stable,normal saline 0.1 ml was injected via the caudal vein for 4 consecutive times at 15 min intervals in C and NL groups.In I+R,I+R+B and I+R+NL groups,0.1 ml remifentanil 10 μg/kg was injected via the caudal vein for 4 consecutive times at 15 min intervals,and the model of incisional pain was established after the first administration.The mechanical paw withdrawal threshold (MWT) and tail-flick latency (TFL) were measured at 24 h before normal saline or remifentanil administration (T0) and at 3,6,24 and 48 h after the end of administration (T1-4).The animals were sacrificed after measurement of pain threshold at T4,and L4-6 segments of the spinal dorsal horn were then collected for determination of the expression of NL-1 protein and mRNA and AMPA receptors,and the ratio of AMPA receptor expression in the membrane protein to that in the total protein (m/t ratio) was calculated.Results Compared with group C,the MWT was significantly decreased,and TFL was shortened at T1-4,the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was up-regulated,and m/t ratio was increased in I+R and I+R+B groups (P＜0.05).Compared with I+R and I+R+B groups,the MWT was significantly increased and TFL was prolonged at T1-4,the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was down-regulated,and m/t ratio was decreased in group I+R+NL (P＜0.05).Conclusion NL-1 in spinal cord dorsal horns can promote the trafficking of GluR1-containing AMPA receptors to cell membrane,which is involved in the development and maintenance of remifentanil-induced hyperalgesia in mice with incisional pain.
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Objective To evaluate the role of spinal COX-1 and COX-2 in remifentanil-induced hyperalgesia in mice with incisional pain.Methods Thirty-two male C57BL/6J mice,aged 8-10 weeks,weighing 20-25 g,were divided into 4 groups (n =8 each) using a random number table method:control group (group C),incisional pain plus remifentanil group (group IR),incisional pain plus remifentanil plus selective COX-1 inhibitor group (group IR+SC560),and incisional pain plus remifentanil plus selective COX-2 inhibitor group (group IR+SC236).In IR,IR+SC560 and IR+SC236 groups,normal saline 10 μl,SC560 25 μg and SC236 25 μg were intrathecally injected,respectively,15 min later remifentanil 10 μg/kg was injected via the tail vein for 4 times at 15 min intervals.An incisional pain model was established after the first injection of remifentanil.The mechanical paw withdrawal threshold (MWT) was measured at 24 h before normal saline or remifentanil injection and 3,6,24 and 48 h after the last injection (T0-T4).The mice were sacrificed after the last measurement of pain threshold,and the L4-6 segments of the spinal cord were removed for determination of the expression of COX-1 and COX-2 (by Western blot)and expression of COX-1 and COX-2 mRNA (by quantitative real-time polymerase chain reaction).Results Compared with group C,the MWT was significantly decreased,and the expression of COX-2 protein and mRNA was up-regulated in IR,IR+SC560 and IR+SC236 groups (P＜0.05).Compared with group IR,the MWT was significantly increased in IR+SC560 and IR+SC236 groups (P＜0.05).There was no significant difference in the MWT at each time point between IR+SC560 and IR+SC236 (P＞0.05).There was no significant difference in the expression of COX-2 protein and mRNA among group IR,group IR+SC560 and group IR+SC236 (P＞0.05).There was no significant difference in the expression of COX-1 protein and mRNA among the four groups (P＞0.05).Conclusion Compared with COX-1,spinal COX-2 plays a major role in the pathophysiological mechanism of remifentanil-induced hyperalgesia in mice with incisional pain.
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Objective@#To evaluate the role of neuroligin 1 (NL-1) in trafficking of GluR1-containing AMPA receptor to cell membrane in spinal cord dorsal horns during remifentanil-induced hyperalgesia in mice with incisional pain.@*Methods@#Forty SPF healthy male C57BL/6J mice, aged 8-10 weeks, weighing 18-22 g, were divided into 5 groups (n=8 each) using a random number table method: control group (group C), NL1-shRNA plasmid group (group NL), incisional pain plus remifentanil group (group I+ R), incisional pain plus remifentanil plus blank vector group (group I+ R+ B), and incisional pain plus remifentanil plus NL-1-shRNA plasmid group (group I+ R+ NL). Negative lentivirus was intrathecally injected in group I+ R+ B.In NL and I+ R+ NL groups, 10 μl NL-1-shRNA lentivirus at 1×108 IFU/ml was intrathecally injected once a day for 3 consecutive days.Normal saline 10 μl was intrathecally injected at the same time point in C and I+ R groups.After transfection was stable, normal saline 0.1 ml was injected via the caudal vein for 4 consecutive times at 15 min intervals in C and NL groups.In I+ R, I+ R+ B and I+ R+ NL groups, 0.1 ml remifentanil 10 μg/kg was injected via the caudal vein for 4 consecutive times at 15 min intervals, and the model of incisional pain was established after the first administration.The mechanical paw withdrawal threshold (MWT) and tail-flick latency (TFL) were measured at 24 h before normal saline or remifentanil administration (T0) and at 3, 6, 24 and 48 h after the end of administration (T1-4). The animals were sacrificed after measurement of pain threshold at T4, and L4-6 segments of the spinal dorsal horn were then collected for determination of the expression of NL-1 protein and mRNA and AMPA receptors, and the ratio of AMPA receptor expression in the membrane protein to that in the total protein (m/t ratio) was calculated.@*Results@#Compared with group C, the MWT was significantly decreased, and TFL was shortened at T1-4, the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was up-regulated, and m/t ratio was increased in I+ R and I+ R+ B groups (P<0.05). Compared with I+ R and I+ R+ B groups, the MWT was significantly increased and TFL was prolonged at T1-4, the expression of NL-1 protein and mRNA and GluR1-containing AMPA receptors in membrane and total proteins was down-regulated, and m/t ratio was decreased in group I+ R+ NL (P<0.05).@*Conclusion@#NL-1 in spinal cord dorsal horns can promote the trafficking of GluR1-containing AMPA receptors to cell membrane, which is involved in the development and maintenance of remifentanil-induced hyperalgesia in mice with incisional pain.
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Objective To evaluate the relationship between remifentanil-induced hyperalgesia and Antamins family member membrane protein 16C ( TMEM16C) and Slack channel in the spinal dorsal horn of rats with incisional pain. Methods Forty-eight male Sprague-Dawley rats, aged 1 month, were studied. The study was performed in two parts. Experiment Ⅰ Twenty-four rats were divided into 4 groups ( n=6 each) using a random number table method: normal saline group ( S group ) , virus vector group ( V group) , virus vector plus remifentanil plus incisional pain group ( VRI group) , and AAV5-TMEM16C o-ver-expression plus remifentanil plus incisional pain group (ORI group). Normal saline (S group), virus vector (V group and VRI group) or AAV5-TMEM16C (ORI group) 1 μl was injected via the L4,5 spinal dorsal horn. Remifentanil 1 μg ·kg-1 ·min-1 was infused for 60 min via the caudal vein at 30 days, and the incisional pain model was simultaneously established in VRI and ORI groups. The thermal paw withdrawal latency ( TWL) and mechanical paw withdrawal threshold ( MWT) were measured at 24 h before remifen-tanil infusion ( T0 ) and 2, 6, 24, and 48 h after stopping infusion ( T1-4 ) . The L4,5 segments of spinal dorsal horns were obtained at the end of the behavioral testing, and the expression of TMEM16C and Slack in total and membrane proteins was determined by Western blot. ExperimentⅡ Twenty-four rats were di-vided into 4 groups ( n=6 each) using a random number table method: normal saline plus artificial cerebro-spinal fluid (ACSF) group (SA group), virus vector plus ACSF group (VA group), virus vector plus remifentanil group ( VR group ) , and AAV5-TMEM16C over-expression plus remifentanil group ( OR group). Normal saline (SA group), virus vector (VA group and VR group) or AAV5-TMEM16C (OR group) 1μl were injected via the spinal dorsal horn at the level of L4,5 . L4,5 spinal cord slices were obtained at 30 days and incubated for 60 min in ACSF ( SA and VA groups ) or in ACSF containing 4 nmol∕L remifentanil ( VR group and OR group) . The whole-cell patch-clamp was used to measure the frequency and amplitude of the Slack channel current after the end of incubation in each group. Results ExperimentⅠCompared with S group, the TWL was significantly shortened and the MWT was decreased at T1-4 , and the expression of TMEM16C and Slack in total and membrane proteins was down-regulated in VRI group ( P<0. 05) . Compared with VRI group, the TWL was significantly prolonged and the MWT was increased at T1-4 , and the expression of TMEM16C and Slack in total and membrane proteins was up-regulated in ORI group ( P<0. 05) . Experiment Ⅱ Compared with SA group, the amplitude and frequency of Slack chan-nel current in spinal dorsal horns were significantly decreased in VR group ( P<0. 05) . Compared with VR group, the amplitude and frequency of the Slack current were significantly increased in OR group ( P<0. 05) . Conclusion The mechanism of remifentanil-induced hyperalgesia is related to down-regulating the expression of TMEM16C and further down-regulating the expression of the Slack channel in the spinal dorsal horn of rats with incisional pain.
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Objective To investigate the relationship remifentanil-induced hyperalgesia and func-tion of nitrated glutamate transportor-1 ( GLT-1) and glutamine synthetase ( GS) in the spinal cord of rats with incisional pain. Methods Thirty-two male Sprague-Dawley rats, weighing 260-280 g, aged 2-3 months, in which caudal catheters were successfully implanted, were divided into 4 groups (n=8 each) u-sing a random number table method: control group ( group C) , incisional pain group ( group I) , remifen-tanil group ( group R) and remifentanil plus incisional pain group ( group RI) . Normal saline was intrave-nously infused for 60 min at 0. 1 ml · kg-1 · min-1 in group C. The model of incisional pain was estab-lished, and normal saline was simultaneously infused for 60 min via the tail vein at 0. 1 ml·kg-1 ·min-1 in group I. Remifentanil was infused for 60 min via the tail vein at 1. 0 μg· kg-1 ·min-1 in group R. The model of incisional pain was established, and remifentanil was infused for 60 min via the tail vein at 1. 0μg· kg-1 ·min-1 in group RI. The mechanical paw withdrawal threshold ( MWT) and thermal paw with-drawal latency ( TWL) were measured at 24 h before infusion of remifentanil or normal saline ( T0 ) and at 2, 6, 24 and 48 h after infusion ( T1-4 ) . The rats were sacrificed after the last measuremnet of pain thresh-old, and the L4-6 segment of the spinal cord was removed for determination of the expression of GLT-1 and GS (by Western blot) and expression of nitrated GLT-1 (nGLT-1) and nitrated GS (nGS) (by Western blot) . Ratios of nGLT-1∕GLT-1 and nGS∕GS were calculated. Results Compared with group C, the MWT was significantly decreased and TWL was shortened at T1-4 , the expression of GLT-1 and GS was down-regu-lated, the expression of nGLT-1 and nGS was up-regulated, and ratios of nGLT-1∕GLT-1 and nGS∕GS were increased in I, R and RI groups ( P<0. 05) . Compared with group I and group R, the MWT was signifi-cantly decreased and TWL was shortened at T1-4 , the expression of GLT-1 and GS was down-regulated, the expression of nGLT-1 and nGS was up-regulated, and ratios of nGLT-1∕GLT-1 and nGS∕GS were increased in group RI ( P<0. 05) . Conclusion The mechanism of remifentanil-induced hyperalgesia may be related to impaired function of GLT-1 and GS in the spinal cord of rats with incisional pain.
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Objective To evaluate the relationship between NR2B subunit-containing N-methyl-D-aspartate (NMDA) receptors (NR2B receptors) and Ca2+/calmodulin-dependent protein kinase Ⅱ α (CaMK Ⅱ α) in the spinal cord during remifentanil-induced hyperalgesia in a rat model of incisional pain (IP).Methods Forty male Sprague-Dawley rats in which intrathecal and caudal catheters were successfully placed,weighing 260-280 g,aged 2-3 months,were divided into 4 groups (n=10 each) using a random number table method:control group (group C),remifentanil plus IP group (group RI),NR2B antagonist Ro 25-6981 group (group Ro) and remifentanil plus IP plus Ro 25-6981 group (group RI+Ro).In group C,normal saline 0.1 ml was intrathecally injected,and 10 min later normal saline was infused for 60 min via the tail vein at a rate of0.1 ml · kg-1 · min-1.In group RI,normal saline 0.1 ml was intrathecally injected,and 10 min later remifentanil was infused for 60 min via the tail vein at a rate of 1.0 μg · kg-1 · min-1,and IP was established immediately after onset of remifentanil infusion.In group Ro,Ro 25-6981 (0.1 ml) 10 μg was intrathecally injected,and 10 min later normal saline was infused for 60 min via the tail vein at a rate of 0.1 ml · kg-1 · min-1.In group RI+Ro,Ro 25-6981 (0.1 ml) 10 μg was intrathecally injected,and 10 min later remifentanil was infused for 60 min via the tail vein at a rate of 1.0 μg · kg-1 · min-1,and IP was established immediately after onset of remifentanil infusion.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 24 h before intravenously infusing normal saline or remifentanil and at 2,6,24 and 48 h after the end of infusion (T0-4).The rats were sacrificed after the last behavioral test,and the L4-6 segment of the spinal cord was removed for determination of the expression of NR2B in total and membrane protein (tNR2B and mNR2B) and expression of CaMK Ⅱ α in total protein (tCaMK Ⅱ α) and phosphorylated CaMK Ⅱ α (pCaMKⅡα).The ratios of mNR2B/tNR2B and pCaMKⅡα/tCaMK Ⅱα were calculated.Results Compared with group C,the MWT was significantly decreased,TWL was shortened,the expression of tNR2B,mNR2B,tCaMKⅡα and pCaMKⅡα was up-regulated,and the ratios of mNR2B/tNR2B and pCaMK Ⅱ α/tCaMK Ⅱ α were increased in group RI (P＜0.05 or 0.01).Compared with group RI,the MWT was significantly increased,TWL was prolonged,the expression of tNR2B,mNR2B,tCaMKⅡα and pCaMKⅡα was down-regulated,and the ratios of mNR2B/tNR2B and pCaMK Ⅱ α/tCaMK Ⅱ α were decreased in group RI+ Ro (P＜0.05 or 0.01).Conclusion Enhanced function of NR2B can activate CaMKⅡα during remifentanil-induced hyperalgesia,which may be involved in the mechanism of remifentanil-induced hyperalgesia in a rat model of IP.
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Objective To investigate the changes in the expression of Ca2+/calmodulin-dependent protein kinase Ⅱ α (CaMK Ⅱ α) in the spinal cord and dorsal root ganglia (DRG) during remifentanil-induced hyperalgesia in a rat model of incisional pain (IP).Methods Thirty-two male Sprague-Dawley rats in which caudal vein catheter was successfully placed,aged 260-280 g,were divided into 4 groups (n=8 each) using a random number table method:control group (group C),IP group,remifentanil group (group R) and remifentanil plus IP group (group RIP).Normal saline was infused via the caudal vein for 60 min at a rate of 0.1 ml · kg-1 · min-1 in group C.Normal saline was infused via the caudal vein for 60 min at a rate of 0.1 ml · kg-1 · min-1,and the model of IP was simultaneously established in group IP.Remifentanil was infused via the caudal vein for 60 min at a rate of 1.0 μg · kg-1 · min-1 in group R.Remifentanil was infused via the caudal vein for 60 min at a rate of 1.0 μg · kg-1 · min-1,and the model of IP was simultaneously established in group RIP.Mechanical paw withdrawal threshold (MWT) and thermal paw withdrawal latency (TWL) were measured at 24 h before infusion and 2,6,24 and 48 h after infusion (T0-4).The rats were sacrificed after the last behavioral test,and L4-6 segment of the spinal cord and DRGs were removed for determination of the expression of total and phosphorylated CaMK Ⅱ α (tCaMK Ⅱ α,pCaMK Ⅱ α) by Western blot.The ratio of pCaMK Ⅱ /tCaMK Ⅱ α was calculated.Results Compared with group C,MWT was significantly decreased,TWL was shortened,the expression of tCaMK Ⅱ α and pCaMK Ⅱ α in the spinal cord and DRGs was up-regulated,and the ratio of pCaMK Ⅱ α/tCaMK Ⅱ α was increased in I,R and RIP groups (P＜0.05 or 0.01).Compared with group IP and group R,MWT was significantly decreased,TWL was shortened,the expression of tCaMK Ⅱ α and pCaMK Ⅱ α in the spinal cord and DRGs was up-regulated,and the ratio of pCaMK Ⅱ α/tCaMK Ⅱ α was increased in group RIP (P＜0.05 or 0.01).Conclusion The mechanism by which remifentanil induces hyperalgesia may be related to upregulated expression of CaMK Ⅱ α in the spinal cord and DRGs in a rat model of IP.
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Objective To evaluate the changes in the expression of transient receptor potential vanilloid 1 (TRPV1) in dorsal root ganglions (DRGs) during remifentanil-induced hyperalgesia in the rats with incisional pain.Methods Thirty-two SPF healthy male Sprague-Dawley rats,weighing 240-260 g,aged 2-3 months,in which caudal catheters were successfully implanted,were divided into 4 groups (n=8 each) using a random number table:control group (group C),incisional pain group (group Ⅰ),remifentanil group (group R),and incisional pain + remifentanil group (group I+R).A 1 cm longitudinal incision was made through skin,fascia and muscle of the plantar aspect of the left hindpaw to establish the model of incisional pain.In group R,remifentanil was intravenously infused for 60 min at a rate of 1.2 μg · kg-1 · min-1.In group Ⅰ,the model of incisional pain was established,and the equal volume of normal saline was intravenously infused for 60 min at the same time.In group I+R,the model of incisional pain was established,and remifentanil was intravenously infused for 60 min at a rate of 1.2 μg · kg-1 · min-1 at the same time.In group C,the equal volume of normal saline was intravenously infused for 60 min.The mechanical paw withdrawal threshold (MWT) and thermal paw withdrawl latency (TWL) were measured at 24 h before normal saline or remifentanil infusion (To) and 2,6,24 and 48 h after the end of infusion (T1-4).The rats were sacrificed after the last measurement of pain threshold,and the DRGs of the lumbar segment (L4-6) were removed for determination of the expression of TRPV1 protein and mRNA by Western blot and real-time polymerase chain reaction,respectively.Results Compared with group C,the MWT was significantly decreased,and the TWL was shortened at T1-4,and the expression of TRPV1 protein and mRNA was up-regulated in R,I and I+R groups (P＜0.05).Compared with group R or group I,the MWT was significantly decreased,and the TWL was shortened at T1-4,and the expression of TRPV1 protein and mRNA was up-regulated in group I+R (P＜0.05) Conclusion Up-regulated expression of TRPV1 in DRGs may be involved in the mechanism underlying remifentanil-induced hyperalgesia in the rats with incisional pain.
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Objective To investigate the influencing factors of stereopsis and ocular position changes before and after intermittent exotropia sur-gery. Methods A total of 70 cases diagnosed with intermittent exotropia(squint angle>15△and0.05). There was no statistical difference in the recovery rate of stereopsis and the orthostatic rate of eyes between the groups of 45△and more than 45△. Conclusion Intermittent exotropia surgery can effectively improve the stereopsis and eye po-sition,and the outcomes of surgery are related to the age of surgery. The recovery rate of stereopsis is higher in the patients with intermittent exotro-pia during the visual development period. Regardless of the size of the angle of squint ,early surgery is benefit to the recovery of stereopsis.
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Objective To evaluate the effect of sevoflurane anesthesia on the expression of phosphorylated cAMP response element-binding protein (p-CREB) in the hippocampal neurons of developing rats.Methods Thirty-two healthy male Sprague-Dawley rats, aged 7 days, weighing 10-15 g, were equally and randomly divided into either control group (group C) or sevoflurane anesthesia group (group Sev) using a random number table.Group C inhaled 30％ oxygen for 6 h.Group Sev inhaled 3％ sevoflurane for 6 h.Eight rats in each group were sacrificed immediately after the end of oxygen or sevoflurane inhalation, and the hippocampus was removed for determination of the expression of p-CREB.The rats at ages 2 months underwent Morris water maze test.The rats were then sacrificed, and the hippocampus was removed for determination of the expression of p-CREB by Western blot.Results Compared with group C, the escape latency and swimming distance were significantly prolonged, the frequency of crossing the original platform was decreased, the percentage of the time of staying at the quadrant Ⅱ was decreased, and the expression of p-CREB in hippocampal neurons was down-regulated in group Sev.Conclusion The mechanism of sevoflurane anesthesia-induced neurotoxicity is related to inhibition of p-CREB expression in hippocampal neurons of developing rats.
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Objective To investigate the role of hippocampal α7 nicotinic acetylcholine receptor (α7nAChR) in sevoflurane-induced deficit in long-term cognitive function in neonatal rats.Methods Sixty-four male Sprague-Dawley rats,aged 7 days,weighing 10-15 g,were randomly divided into 4 groups (n =16each) using a random number table:control group (group C),sevoflurane anesthesia group (group S),sevoflurane anesthesia + α7nAChR agonist PNU-282987 group (group PS),and α7nAChR inhibitor MLA group (group M).In C and S groups,the rats inhaled 30％ oxygen and 3％ sevoflurane for 6 h,respectively.In group PS,PNU282987 (5 mg/kg) was injected intraperitoneally and 24 h later the rats were exposed to 3％ sevoflurane for 6 h.In group M,MLA 3 mg/kg was injected intrappritoneally and 24 h later the rats inhaled 30％ oxygen for 6 h.Eight rats in each group were randomly chosen and sacrificed immediately after oxygen or sevoflurane inhalation.The hippocampus was renoved for determination of the expression of α7nAChR and NR1,NR2A and NR2B subunitscontaining NMDA receptors in the total protein and membrane protein in hippocampal neurons.When the left rats in each group were raised to 2 months,Y-maze test was performed to detect the cognitive function.Results Compared with group C,the expression of α7nAChR and NR1,NR2A and NR2B subunits-containing NMDA receptors in the membrane protein was significantly down-regulated,and the percentage of spontaneous alternation was decreased in group S,the expression of NRI and NR2A subunits-containing NMDA receptors in the membrane protein was down-regulated (P ＜ 0.05),and no significant change was found in the expression of NR2B subunitscontaining NMDA receptors in the membrane protein and percentage of spontaneous alternation in group PS (P ＞ 0.05),and no significant change was found in the expression of NR1 and NR2A subunits-containing NMDA receptors in the membrane protein (P ＞ 0.05),and the expression of NR2B subunits-containing NMDA receptors in the membrane protein was down-regulated,and the percentage of spontaneous alternation was decreased in group M (P ＜ 0.05).Compared with group S,no significant change was found in the expression of NR1 and NR2A subunits-containing NMDA receptors in the membrane protein (P ＞ 0.05),and the expression of NR2B subunitscontaining NMDA receptors in the membrane protein was significantly up-regulated,and the percentage of spontaneous alternation was increased in PS group (P ＜ 0.05).There was no significant difference in the expression of α7nAChR and NR1,NR2A and NR2B subunits-containing NMDA receptors in the total protein and the number of entries into each arm in Y-maze test between the four groups (P ＞ 0.05).Conclusion The mechanism by which sevoflurane induces deficit in long-term cognitive function may be related to decreased function of hippocampal α7nAChR and inhibition of function of NMDA receptors in neonatal rats.