ABSTRACT
OBJECTIVE@#To determine the changes of Mu-opioid receptor (Mor) and neuron-restrictive silencer factor (NRSF) in periaquductal gray (PAG) in mouse models of remifentanil-induced postoperative hyperalgesia.@*METHODS@#Thirty-two Kun-Ming mice were randomly divided into 4 groups (8 mice in each group): Group C (mice underwent a sham procedure and saline was infused subcutaneously over a period of 30 min), Group I (mice underwent a surgical incision and the same volume of saline), Group R (mice underwent a sham procedure and remifentanil was infused subcutaneously at the moment of surgical incision over a period of 30 min), and group IR (mice underwent a surgical incision and remifentanil). Paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) tests were performed 24 h before the operation and 2, 6, 24, and 48 h after the operation. The specimens were collected after behavioral testings at 48 h. The expressions of Mor and NRSF in mice's PAG neurons were determined by Western blot.@*RESULTS@#Mechanical allodynia and thermal hyperalgesia developed in Group I, R and IR (P<0.01). Intraoperative infusion of remifentanil enhanced mechanical allodynia and thermal hyperalgesia in mice with planta incision (P<0.01). In Group R and Group IR, the expression of Mor was significantly lower (P<0.01) and NRSF was significantly higher (P<0.01) when compared with Group C and Group I.@*CONCLUSION@#Intraoperative infusion of remifentanil induces postoperative hyperalgesia in mouse models, accompanied with decreased expressions of Mor and increased of NRSF level in PAG neurons, which may be involved in remifentanil induced hyperalgesia.
Subject(s)
Animals , Mice , Disease Models, Animal , Hyperalgesia , Pain, Postoperative , Periaqueductal Gray , Metabolism , Piperidines , Receptors, Opioid, mu , Metabolism , Remifentanil , Repressor Proteins , MetabolismABSTRACT
Objective To investigate the effects of intrathecal injection of α-cyano-4-hydroxy-cinnamate (4-CIN) in rats with neuropathic pain induced by chronic constriction injury of sciatic nerve (CCI).Methods Eighteen male SD rats were divided randomly into 3 groups(n=6):sham group (group S),CCI model group (group C0) and 4-CIN group (group C1).Group C0 and C1 were operated with the model of neuropathic pain induced by chronic constriction injury of sciatic nerve ; and group S were treated as sham operated rats.Two days after operation,group C1 received intrathecal injection of 100 μmol 4-CIN dissolved in 10％ DMSO 10 μl,while group C0 received intrathecal injection of 10％ DMSO 10 μl only.The paw withdrawal thermal latency(PWTL) and paw withdrawal mechanical threshold(PWMT) were tested 1 d before operation and 1 d,3 d,7 d,10 d,14 d after operation(T0-5).Results The basic values of PWMT and PWTL before operation showed no statistically significant differences among the three groups.On T1-5,the PWMT((11.71 ±2.81) g,(9.76± 1.00) g,(8.22± 1.33) g,(6.50± 1.48) g,(4.67± 1.03) g) and PWTL((11.36±2.18) s,(11.60±2.54) s,(8.54± 1.42) s,(7.59± 1.00) s,(6.88± 0.42) s) in group C0 were significantly lower than those in group S (P＜0.05).However,there were no significant differences between group S and C1 on T2-5(P＞0.05).Conclusion Intrathecal administration of 4-CIN can attenuate neuropathic pain in rats induced by CCI.
ABSTRACT
Objective To investigate the effects of repeated intrathecally kinesin superfamily protein 17 (KIF17) antisense oligodeoxynucleotide (ODN) on the expression of mLin10 and NR2B in spinal cord in a mouse model of bone cancer pain.Methods Fifty-six male C3H/HeJ mice,aged 4 ～ 6 weeks,weighting 20 ～ 25 g,were randomly divided into two groups:sham operation group (group S,n=20) and bone cancer pain group (group T,n=36).20μl α-minimal essence medium (α-MEM) which containing 2× 105 NCTC2472 osteosarcoma cells was injected into the intramedullary space of the right femur in group T.In group S,no cancer cell was instead.The number of spontaneous flinches (NSF) and the paw withdrawal mechanical threshold (PWMT) were measured at the day before (base) and the days 4,7,10 and 14 after inoculation.According to the corresponding time points,twenty-four mice were sacrificed for determination the expression of KIF17,mLin10 and NR2B using Western blot.Then,the mice of group T were randomly divided into three groups (n=8,T1,T2,T3,group).In group S and group T1,Saline 5 μl was injected intrathecally.KIF17 sense ODN and antisense ODN,5 μg/5μl were respectively injected in group T2 and T3 for 6 consecutive days.Pain behaviors were assessed at the days 2-6 after the first injection.And determinated the KIF17,mLin10 and NR2B expression,again.Results Compared with group S,the NSF was increased and the PWMT was decreased at the days 7,10 and 14 after inoculation in group T (P＜0.05).Compared with the base ((0.65±0.15),(1.06±0.06),(1.01±0.14)),the expression of KIF17,mLin10 and NR2B (14d:(1.13 ±0.06),(2.17 ± 0.37),(1.85 ± 0.32)) were increased at the days 7,10 and 14 after inoculation in group T(P＜0.05).During the course of the injection,compared with group T1 and T2,the NSF was decreased and the PWMT was increased significantly in the group T3(P＜0.05),the expression of KIF17,mLin10 and NR2B((0.88±0.08),(0.96±0.11),(1.03±0.08)) were reduced in group T3 (P＜0.05).Conclusion Intrathecal KIF 17 antisense ODN in the mice of bone cancer pain improves the pain behaviors,and inhibits the up-regulated of KIF17,mLin10 and NR2B during the course of the injection.
ABSTRACT
Objective To evaluate the role of neuron-restrictive silencer factor (NRSF) in the spinal cord in remifentanil-induced hyperalgesia in a mouse model of incisional pain (IP) .Methods Fifty-six male Kunming mice were randomly divided into 7 groups (n=8 each):control group (group C) ,IP group (group I) ,IP +remifentanil group (group IR ) , NRSF antisense oligonucleotide group (NAS group ) , IP + NRSF antisense oligonucleotide group (I+NAS group ) ,IP + remifentanil + NRSF mismatch oligonucleotide group (IR+NMS group) , and IP + remifentanil + NRSF antisense oligonucleotide group (IR + NAS group ) . Artificial cerebrospinal fluid 5 μl was injected intrathecally once a day for 3 consecutive days in C ,I and IR groups .NRSF antisense oligonucleotide NAS 10μg was injected intrathecally once a day for 3 consecutive days in NAS ,I+NAS and IR + NAS groups . NRSF mismatch oligonucleotide 10 μg was injected intrathecally once a day for 3 consecutive days in IR+NMS group .A 1-cm longitudinal incision was made through skin ,fascia and muscle of the plantar aspect of the right hindpaw to establish the model of incisional pain in sevoflurane-anesthetized rats .At 30 min after the last injection ,normal saline 0.4 ml was infused subcutaneously in C and NAS groups ,the model was established and normal saline 0.4 ml was subcutaneously infused simultaneously in I and I+NAS groups ,and the model was established and remifentanil 0.04 mg/kg was subcutaneously infused simultaneously in IR ,IR+NMS and IR+NAS groups .At 3 days before operation (T0 ) ,4 h before operation (T1 ) and 4 ,12 ,24 and 48 h after operation (T1-5 ) ,mechanical paw withdrawal threshold to von Frey stimuli (PMWT ) and paw withdrawal latency to thermal nociceptive stimulus (PTWL ) were measured .Results Compared with C group ,the PWMT and PWTL were significantly decreased at T2-5 in I ,IR ,I+NAS ,IR+NMS and IR+NAS groups ( P0.05 ) .Compared with I group ,the PWMT and PWTL were significantly decreased at T2-5 in IR and IR+NMS groups ( P0.05) . Compared with IR group ,no significant change was found in the PWMT and PWTL at each time point in IR+NMS group ( P>0.05) ,and the PWMT and PWTL were significantly increased at T2-5 in IR+NAS group ( P<0.05) . Conclusion NRSF in the spinal cord is involved in the development and maintenance of hyperalgesia induced by remifentanil in a mouse model of IP .
ABSTRACT
Identification of the function of all genes in the mammalian genome is critical in understanding basic mechanisms of biology. However, the diploidy of mammalian somatic cells has greatly hindered efforts to elucidate the gene function in numerous biological processes by mutagenesis-based genetic approaches. Recently, mouse haploid embryonic stem (haES) cells have been successfully isolated from parthenogenetic and androgenetic embryos, providing an ideal tool for genetic analyses. In these studies, mouse haES cells have already shown that they could be used in cell-based forward or reverse genetic screenings and in generating gene-targeting via homologous recombination. In particular, haES cells from androgenetic embryos can be employed as novel, renewable form of fertilization agent for yielding live-born mice via injection into oocytes, thus showing the possibility that genetic analysis can be extended from cellular level to organism level.