Application and prospect of drug discrimination in field of drug abuse / 中国药理学通报

Drug discrimination is a behavioral pharmacological technique to study the discriminative stimulus effects of drug. Currently drug discrimination has been widely used in preclinical drug development of CNS drugs, the most extensive of which is psychodependent research in the field of drug abuse. This review describes in general the basic principles of drug discrimination, preliminarily elaborates on the relevant characteristics and applications of the subjective effects, time-course effect, stereo specificity, individual differences, and receptor mechanisms, and its development prospects for hallucinogens and cannabis drugs are also presented.

Effect of NBED on decorporation of uranium and protective effect on HK-2 cellular damage / 中国药理学通报

Aim To study the effect of NBED on the decorporation of uranium and the protective effect on HK-2 cellular damage.Methods ICR mice were divided into control group, uranium exposure group(0.03 mg), DTPA-CaNa3(300 mg·kg-1)and NBED(300, 150, 75 mg·kg-1)treatment groups.After injection of uranyl acetate, mice were given different doses of decorporation agents immediately.After 24 h the content of uranium in kidney, bone, liver, spleen and muscle was determined by ICP-MS.HK-2 cells were divided into control group, uranium model group(80 μmol·L-1), DTPA-CaNa3(80 μmol·L-1)and NBED(80, 40, 20 μmol·L-1)treatment group interacted with uranium for 48h.CCK-8 method was used to detect the cell survival rate; light microscope was used to observe the cell morphology; ICP-MS method was used to detect the ratio of uranium endocytosis and uranium efflux; biochemical method was employed to determine SOD, GSH and LDH levels; flow cytometry was applied to determine ROS, apoptosis and cell cycle.Results 300 mg·kg-1 NBED reduced the content of uranium in kidney and bone by 44.3% and 18.8% respectively.Compared with model group, NBED reduced uranium entry into cells by 11%42%, increased uranium emission by 18%48%, increased the survival rate of HK-2 cells, thelevels of SOD and GSH, decreased the expression levels of ROS and LDH, and decreased the apoptotic rate and S phase arrest.DTPA-CaNa3 could significantly reduce the content of uranium and the amount of uranium endocytosis in kidney of mice, but the effect of promoting excretion was significantly lower than that of NBED, and it had no protective effect on the acute injury of HK-2 cells caused by uranium.Conclusions NBED is an effective uranium decorporation agent, which is superior to DTPA-CaNa3 approved by FDA.It could reduce the production of ROS and LDH, increase the content of SOD and GSH, and reduce the arrest and apoptosis of S phase, thus protecting HK-2 cells from uranium induced damage.

Clinical Characteristics and Treatment Outcome of Pseudomonas Peritoneal Dialysis-associated Peritonitis / 中国医学科学院学报

Objective To explore the clinical characteristics and treatment of Pseudomonas peritoneal dialysis-associated peritonitis(PsP). Methods The data of patients receiving peritoneal dialysis in four tertiary hospitals in Jilin province from 2015 to 2019 were retrospectively analyzed.According to the etiological classification,the patients with peritoneal dialysis-associated peritonitis(PDAP)were classified into PsP group and non-PsP group.The incidence of PsP was calculated,and the clinical characteristics and treatment outcomes of the two groups were compared.Kaplan-Meier method was used to draw the survival curve,and Cox regression was performed to analyze the risk factors affecting the technical failure of PsP.The treatment options of Pseudomonas aeruginosa-caused PDAP and the drug sensitivity of PsP were summarized. Results A total of 1530 peritoneal dialysis patients with complete data were included in this study,among which 439 patients had 664 times of PDAP.The incidence of PsP was 0.007 episodes/patient-year.PsP group had higher proportion of refractory peritonitis(41.38% vs.19.69%,P=0.005),lower cure rate(55.17% vs.80.79%, P=0.001),and higher extubation rate(24.14% vs.7.09%,P=0.003)than non-PsP group.The technical survival rate of PsP group was lower than that of non-PsP group(P<0.001).Multivariate Cox regression analysis showed that Pseudomonas aeruginosa was an independent risk factor for technical failure in patients with PsP(HR=9.020,95%CI=1.141-71.279,P=0.037).Pseudomonas was highly sensitive to amikacin,meropenem,and piperacillin-tazobactam while highly resistant to compound sulfamethoxazole,cefazolin,and ampicillin. Conclusion The treatment outcome of PsP is worse than that of non-PsP,and Pseudomonas aeruginosa is an independent risk factor for technical failure of PsP.

Venous thromboembolism in the emergency department: A survey of current best practice awareness in physicians and nurses in China / 世界急诊医学杂志（英文）

BACKGROUND@# For emergency department (ED) patients, risk assessment, prophylaxis, early diagnosis and appropriate treatment of venous thromboembolism (VTE) are essential for preventing morbidity and mortality. This study aimes to investigate knowledge amongst emergency medical staff in the management of VTE.@*METHODS@# We designed a questionnaire based on multiple scales. The questionnaire was distributed to the medical and nursing clinical staff in the large urban ED of a medical center in Northern China. Data was described with percentages and the Kruskal-Wallis test was used to compare ranked data between different groups. The statistical analysis was done using the SPSS 22.0 software.@*RESULTS@# In this survey, 180 questionnaires were distributed and 174 valid responses (response rate of 96.67%) were collected and analyzed. In scores of VTE knowledge, no significant differences were found with respect to job (doctor vs. nurse), the number of years working in clinical medicine, education level, and current position, previous hospital experience and nurses' current work location within the ED. However, in pair wise comparison, we found participants who worked in ED for more than 5 years (n=83) scored significantly higher on the questionnaire than those under 5 years (n=91) (95.75 vs. 79.97, P=0.039). There was a significant difference in some questions based on gender, age, job, and nurse work location, number of working years, education level, and different ED working lifetime.@*CONCLUSION@# Our survey has shown deficiencies among ED medical staff in knowledge and awareness of the management of VTE. We recommend several changes be considered, such as the introduction of an interdisciplinary workshop for medical staff; the introduction of a standardized VTE protocol; a mandatory study module on VTE for new physicians and nurses; the introduction of a mandatory reporting system for adverse events (including VTE).

Effects of Niaoduqing Particles () on Delaying Progression of Renal Dysfunction: A Post-trial, Open-Label, Follow-up Study / 中国结合医学杂志

OBJECTIVE@#To follow up the participants of the randomized clinical trial "Efficacy and Safety of Niaoduqing Particles () for Delaying Moderate-to-Severe Renal Dysfunction", and assess the long-term effects of Niaoduqing Particles on delaying the progression of renal dysfunction.@*METHODS@#Participants, who had previously been randomly assigned to receive Niaoduqing Particles or placebo for 24 weeks (146 cases in each group), were invited to follow-up and all were administered Niaoduqing Particles 5 g thrice daily and 10 g before bedtime for 24 weeks. The primary endpoints were changes in baseline serum creatinine (Scr) and estimated glomerular filtration rate (eGFR) after completion of the open-label treatment period.@*RESULTS@#After the double-blind period, the median (interquartile range) changes in Scr were 1.1 (-13.0-24.1) and 11.7 (-2.6-42.9) μmol/L for the Niaoduqing Particle and placebo groups, respectively (P=0.008), and the median changes in eGFRs were-0.2 (-4.3-2.7) and-2.21 (-5.7-0.8) mL•min•1.73 m, respectively (P=0.016). There were significant differences in the double-blind period changes in renal function between groups. After the open-label period, the median changes in Scr were 9.0 (-10.0-41.9) and 17.5 (-6.0-50.0) μmol/L for the Niaoduqing Particle and placebo groups according to baseline grouping, respectively (P=0.214), and the median changes in eGFRs were-2.3 (-6.4-1.9) and-3.7 (-7.5-1.1) mL•min•1.73 m, respectively (P=0.134). There were no statistical differences in the open-label period changes in renal function between groups. The eGFR reduction of participants who accepted Niaoduqing Particle treatment for 48 weeks was projected to 2.5 mL•min•1.73 m per year.@*CONCLUSION@#Niaoduqing Particles appear to have long-term efficacy for patients with moderate-to-severe renal dysfunction. Although there was no statistical difference, the early use of Niaoduqing Paticles seems to ameliorate the worsening of renal function. (Trial registration No. ChiCTR-TRC-12002448).

Night Sleep Duration and Risk of Cognitive Impairment in a Chinese Population: A Cross-sectional Study / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Although sleep is one of the most important health-related behavioral factors, the association between night sleep duration and cognitive impairment has not been fully understood. A cross-sectional study was conducted with a random sample of 2,514 participants (⋝ 40 years of age; 46.6% women) in China to examine the association between night sleep duration and cognitive impairment.</p><p><b>METHODS</b>Night sleep duration was categorized as ⋜ 5, 6, 7, 8, or ⋝ 9 h per night. Cognitive function was measured using the Mini-Mental State Examination. A multivariate regression analysis was used to analyze the association of night sleep duration with cognitive impairment. A total of 122 participants were diagnosed with cognitive impairment.</p><p><b>RESULTS</b>A U-shaped association between night sleep duration and cognitive impairment was found. The odds ratios (95% confidence intervals) of cognitive impairment (with 7 h of daily sleep being considered as the reference) for individuals reporting ⋜ 5, 6, 8, and ⋝ 9 h were 2.14 (1.20-3.83), 1.13 (0.67-1.89), 1.51 (0.82-2.79), and 5.37 (1.62-17.80), respectively (P ⋜ 0.01).</p><p><b>CONCLUSION</b>Short or long night sleep duration was an important sleep-related factor independently associated with cognitive impairment and may be a useful marker for increased risk of cognitive impairment..</p>

Comparison of short term curative effects of open door laminoplasty with different plate density for the treatment of multi segment cervical spondylotic myelopathy / 中国骨伤

<p><b>OBJECTIVE</b>To compare the short term curative effect of posterior open door laminoplasty between continuous placement of shaping plate and intermittent placement in treating multilevel cervical spondylotic myelopathy.</p><p><b>METHODS</b>From January 2012 to March 2015, 43 patients with multi segment cervical spondylotic cervical were treated with posterior open door laminoplasty, 21 patients with continuous placement of shaping plate(continuous group), 22 patients with intermittent placement of shaping plate(intermittent group). Operative time, intraoperative blood loss, JOA score, VAS score, postoperative spinal sagittal diameter and cervical curvature, postoperative cervical activity, complications, hospitalization expenses etc. were observed.</p><p><b>RESULTS</b>The patients of two groups were followed up with an average of (23.2±8.1) months and (23.3±8.0) months in continuous group and intermittent group, respectively. There was no significant difference in operative time, intraoperative blood loss, hospitalization time between two groups(>0.05). JOA and VAS scores of all patients at final follow up were obviously improved than preoperative(<0.05). Postoperative spinal sagittal diameter at 3 days and final follow up were obviously improved(<0.05), and there was no significant difference between postoperative at 3 days and final follow up(>0.05). Cervical activity of all patients at final follow up was decreased than preoperative(<0.05), but there was no significant difference between two groups(>0.05). There was no significant difference in postoperative complication and there was significant difference in hospitalization expenses between two groups.</p><p><b>CONCLUSIONS</b>Posterior open door laminoplasty with continuous or intermittent placement of shaping plate have similar clinical effects in ameliorating nerve function for the treatment of multilevel cervical spondylotic myelopahty. However, the hospitalization expenses of intermittent group is obviously reduced, and the medical resources can be saved.</p>

Clinical study of cervical anterior and posterior decompression and internal fixation in the revision of anterior cervical fixation failure / 中国骨伤

<p><b>OBJECTIVE</b>To investigate the clinical effects and prevent the complications of posterior and anterior decompression and internal fixation in the revision of cervical anterior internal fixation failure.</p><p><b>METHODS</b>From 2008 January to 2011 December, 17 patients with cervical anterior internal fixation failure were treated with posterior and anterior decompression and internal fixation. There were 12 males and 5 females, aged from 26 to 68 years old with an average of 44.1 years. The lower screw loosening was found in 6 cases, the upper screw loosening in 5 cases, titanium mesh caving in 3 cases, the upper screw breakage in 2 cases, the lower screw breakage in 1 case. Informations of bone fusion were observed by X-ray, CT, MRI. Clinical effects were evaluated by modified JOA score.</p><p><b>RESULTS</b>All the revision operations were successfully completed. One case with poor blood coagulation function before operation resulted in postoperative hematoma and occurred neurological symptoms; after hematoma removal and fresh frozen plasma infusion later, neurological symptoms of the patient disappeared. All patients were followed up from 6 to 38 months with an average of (22.4±10.0) months. Postoperative at 2 weeks, 3 months, and final follow-up, JOA score had obviously improved and respectively was 13.1±1.6, 13.4±1.6, 14.2±1.5. All internal fixation locations were good after revision,and obtained bone fusion at 10 months after operation, with an average fusion time of 6 months.</p><p><b>CONCLUSION</b>The combined posterior and anterior decompression and internal fixation in the revision of cervical anterior internal fixation failure is safe, can achieve thoroughly decompression, maintain the cervical curvature, reconstruct the three column stability, and it may be used for the patients of cervical anterior fixation failure.</p>

Protective effect of tert-butylhydroquinone on PC12 cells from neurotoxicity induced by manganese in vitro / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the protective effect of the tert-butylhydroquinone (tBHQ) on PC12 cells from neurotoxicity induced by manganese.</p><p><b>METHODS</b>Cytotoxicity of PC12 cells was measured by MTT assay, following the PC12 cells treatment with different concentrations of MnCl₂ (300, 600, 900 μmol/L) for 24, 48 or 72 h. PC12 cells were pretreated with 40 μmol/L tBHQ for 12 h, followed by the treatment of 600 micromol/L or 300 μmol/L MnCl₂ for 72 h. Cytotoxicity of PC12 cells was measured by MTT assay, and cell apoptosis was examined by the method of Annexin V-FITC/PI in flow cytometry (FCM).</p><p><b>RESULTS</b>The proliferation of PC12 cells treated with 300, 600, 900 μmol/L MnCl2 was suppressed in the dose dependent pattern (P < 0.01). Proliferation of PC12 cells treated with 600 μmol/L MnCl₂ was suppressed to 40% of that in control group (P < 0.01), but the proliferation rate of PC12 cell pretreated with 40 μmol/L tBHQ was 180% of that in control group (P < 0.01). Apoptotic rate of PC12 cells treated with 300 micromol/L MnCl₂ was higher than the vehicle control group (P < 0.01). Apoptotic rate of 40 μmol/L tBHQ pretreatment followed by 300 μmol/L MnCl₂ treatment was lower than that of MnCl2 treatment group (P < 0.01). The inhibition rate of apoptosis was 61%.</p><p><b>CONCLUSIONS</b>Manganese may suppress PC12 cells proliferation and induce apoptosis. tBHQ can reduce PC12 cells proliferation suppressed by manganese and attenuate the apoptosis induced by manganese.</p>

Effect of electroacupuncture on drug-seeking behaviors induced by heroin priming and FosB expression in relevant brain regions / 中南大学学报(医学版)

OBJECTIVE@#To explore the effect of electroacupuncture on heroin seeking behavior and FosB expression in relevant brain regions.@*METHODS@#Rat model of heroin relapse behaviors was developed with progressive fixed ratio program,and model rats were randomly divided into 3 groups: a restraint group, a needle retention group, and a electroacupuncture group. The heroin seeking behavior was elicited by a small dose of heroin. FosB expression in relevnt brain region was assessed with immunohistochemical technique.@*RESULTS@#Tests on reinstatement of drug seeking behavior induced by heroin priming showed that compared with the restraint group, active pokes in the electroacupuncture group decreased significantly(P<0.05). Compared with the restraint group, the expression of FosB positive nuclei in Acd, Pcg and CeA of rats brain both in the electroacupuncture group and the needle retention group (P<0.05) decreased significantly. In LC, the expression of FosB positive nuclei in the needle retention group decreased significantly compared with the restraint group (P<0.05).@*CONCLUSION@#Continuous acupuncture and needle retention attentuate the reinstatement of heroin-seeking behaviors induced by heroin priming, and the inhibitory effect may be mediated partially by the expression of FosB in relevant regions which are involved in the process of heroin addiction.

Effects of catgut embedding at "Zusanli" (ST 36) and "Shenshu" (BL 23) on morphine analgesic tolerance and locomotor sensitization in the rat / 中国针灸

<p><b>OBJECTIVE</b>To compare effects of catgut embedding at "Zusanli" (ST 36) and "Shenshu" (BL 23) on Morphine analgesic tolerance and locomotor sensitization induced by chronic Morphine administration and the mechanism.</p><p><b>METHODS</b>The rats were randomly divided into a model group, a non-acupoint group, a Shenshu group and a Zusanli group. The rats, except those in the model group, were pretreated with acupoint catgut-embedding 10 days before the first Morphine injection. The Morphine-tolerance model was established and the pain threshold was detected by hot-plate test every day. Locomotor activities were recorded after the first Morphine injection and Morphine-challenging 1 week after withdrawal of Morphine. The positive neurons of nitric oxide synthetase (NOS) were showed by NADPH-d histochemical method.</p><p><b>RESULTS</b>Compared with the non-acupoint group, catgut embedding at "Zusanli" (ST 36) could attenuate the Morphine analgesic tolerance and the increase of locomotor activities in rats. Meanwhile, the expression of NOS positive neurons in nucleus accumbens septi and dorsal striatum decreased in the Zusanli group. There were no significant differences between the Shenshu group and the non-acupoint group in the analgesic threshold and locomotor sensitization, but the expression of NOS positive neurons in the striatum region significantly decreased.</p><p><b>CONCLUSION</b>Catgut embedding at "Zusanli" (ST 36) can attenuate Morphine analgesic tolerance and reverse formation of locomotion sensitization induced by chronic Morphine administration, which are possibly related with inhibition of the expression of NOS positive neurons in nucleus accumbens septi and dorsal striatum.</p>

Microinjection of M(5) muscarinic receptor antisense oligonucleotide into VTA inhibits FosB expression in the NAc and the hippocampus of heroin sensitized rats / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To investigate the effect of M(5) muscarinic receptor subtype on the locomotor sensitization induced by heroin priming, and it's effect on the FosB expression in the nucleus accumbens (NAc) and the hippocampus in the heroin sensitized rats.</p><p><b>METHODS</b>Locomotor activity was measured every 10 min for 1 h after subcutaneous injection of heroin. FosB expression was assayed by immunohistochemistry, and the antisense oligonucleotides (AS-ONs) targeting M(5) muscarinic receptor was transferred with the lipofectin.</p><p><b>RESULTS</b>Microinjection of AS-ONs targeting M(5) muscarinic receptor in the ventral tegmental area (VTA) blocked the expression of behavioral sensitization induced by heroin priming in rats. Meanwhile, the expression of FosB-positive neurons in either the NAc or the dentate gyrus (DG) of the hippocampus increased in heroin-induced locomotor sensitized rats. The enhancement of FosB-positive neurons in the NAc or DG could be inhibited by microinjection of M(5) muscarinic receptor AS-ONs into the VTA before the heroin-induced locomotor sensitization was performed. In contrast, microinjection of M(5) muscarinic receptor sense oligonucleotide (S-ONs) into the VTA did not block the expression of behavioral sensitization or the expression of FosB in the NAc or DG in the heroin sensitized rats.</p><p><b>CONCLUSION</b>Blocking M(5) muscarinic receptor in the VTA inhibits the expression of heroin-induced locomotor sensitization, which is associated with the regulation of FosB expression in the NAc and hippocampus neurons. M(5) muscarinic receptor may be a useful pharmacological target for the treatment of heroin addiction.</p>

Effects of electroacupuncture of low frequency on heroin-seeking behavior and FosB protein expression in relative brain regions / 中国针灸

<p><b>OBJECTIVE</b>To observe effects of electroacupuncture (EA) of low frequency on heroin-seeking behavior and FosB protein expression in relative brain regions so as to explore the mechanism of EA.</p><p><b>METHODS</b>Rat model of relapsing into heroin was established with progressive fixed ratio program, and model rats were randomly divided into 3 groups: a "Sanyinjiao" needle-retention control group, a low frequency and weak EA group, and a low frequency and strong EA group. Heroin-seeking behavior was elicited by conditional clue and small dose of heroin; FosB protein expression was investigated with immunohistochemical technique.</p><p><b>RESULTS</b>After treatment, the heroin-seeking behavior induced by conditional clue decreased in the needle-retention control group and the weak EA group, and the heroin-seeking behavior induced by small dose of heroin in the weak EA group significantly reduced as compared with the control group, and FosB protein expression in the nucleus accumbens septi, globus pallidus, basolateral amygdaloid nucleus significantly decreased in the weak EA group, and did not significantly change in the strong EA group; the activity induced by heroin increased as compared with those in the control group and the weak EA group.</p><p><b>CONCLUSION</b>EA of low frequency and low intensity can cure the heroin-seeking behavior, which is correlated with regulating nervous adaptation of nucleus accumbens septi, basolateral amygdaloid nucleus, etc..</p>

Muscarinic receptors modulate the mRNA expression of NMDA receptors in brainstem and the release of glutamate in periaqueductal grey during morphine withdrawal in rats / 生理学报

The antisense approach and RT-PCR were used to study the effects of muscarinic receptors on the scores of morphine-withdrawal syndrome and the expression of NMDA receptor subtypes (NR(1A) and NR(2A)) mRNA in rat spinal cord and brainstem. The concentrations of glutamate in periaqueductal grey (PAG) of morphine-withdrawal rats were determined by capillary electrophoresis with laser-induced fluorescence detection. The data showed that the NR(1A) and NR(2A) mRNA levels were increased significantly in the spinal cord and brainstem 1 h after the injection of naloxone (4 mg/kg, i.p.) in morphine-dependent rats. Moreover, in morphine-dependent rats pretreated (i.p.) with scopolamine (0.5 mg/kg), or pirenzepine (10 mg/kg), MK801 (0.125 mg/kg), L-N-nitroarginine methylester (10 mg/kg) 30 min before naloxone injection, the NR(1A) and NR(2A) mRNA levels were significantly lower than those of 1 h morphine-withdrawal rats. Intrathecal injection of NR(1A) or M(2) receptor antisense oligonucleotides (A-oligo, 4 microg/per rat) 24 h prior to naloxone challenge could block the morphine withdrawal symptoms including wet dog shaking, irritability, salivation, diarrhea, chewing and weight loss. Meanwhile, in morphine-dependent rats the NR(1A) mRNA levels in the spinal cord and brainstem were down-regulated by intrathecal injection of M(2) receptor A-oligo. The glutamate concentrations in PAG microdialysis were increased to a maximal level 15 min after naloxone injection. The glutamate response was inhibited by pretreatment with M(2) receptor A-oligo but not by M(1) A-oligo. The results suggest that the expression of NMDA receptors and the release of glutamate in brainstem are involved in the processes of morphine withdrawal and that the NMDA receptor expression is possibly regulated by the muscarinic receptors during morphine withdrawal.

Application of combination of capillary electrophoresis with laser-induced fluorescence: measurement of glutamate and arginine in PAG microdialytes of conscions morphine-withdrawal rats / 生理学报

Microdialysis technique in free-moving animals can be used to monitor continuously the changes of many extracellular neurotransmitters in certain brain areas and study the relationship between neurotransmitter and functions. Using detection of capillary electrophoresis combined with laser-induced fluorescence (CE-LIF) further improves the above-mentioned technique. In the present study, fluorescein isothiocyanate (FITC) was used to derivatizate amino acid in very low concentration. We found that increasing derivatization temperature could shorten derivatization time and that the derivatizative efficiency was not different from that when experiment was performed under the traditional derivatization condition (room temperature for 16 h). We also got an optimized condition of amino acid derivatization with FITC at 30 degrees C water bath for 5 h. Using the optimized condition of amino acid derivatization, we investigated the changes in L-arginine (L-Arg) and L-glutamate (L-Glu) concentration in periaqueductal gray matter (PAG) microdialytes of free-moving morphine-withdrawal rats. The results indicated that there was no significant difference in the concentration of L-Arg and L-Glu in PAG between non-dependent and dependent rats. The concentration of L-Arg and L-Glu in PAG increased by 63% and 105%, respectively, in the first 10 min after naloxone-precipitated withdrawal and then declined gradually. These changes were in correspondence with the scores of morphine withdrawal symptom.

mRNA expression of muscarinic receptors in spinal cord and brainstem in morphine dependent rats / 药学学报

<p><b>AIM</b>To observe mRNA expression of muscarinic acetylcholine receptors in spinal cord and brainstem in morphine dependent or withdrawal rats.</p><p><b>METHODS</b>The mRNA expression level of m1, m2, m3, m4 and m5 were determined by RT-PCR, the beta-actin mRNA expression was used as internal control.</p><p><b>RESULTS</b>The mRNA level of m1, m2, m3, m4 and m5 in spinal cord and m1 and m2 in brainstem were increased significantly during morphine dependence, and the levels of m1, m2, m3 and m4 in spinal cord and m1 in brainstem were decreased 1 h after the injection of naloxone (4 mg.kg-1, i.p.) in morphine dependent rats. Either scopolamine (0.5 mg.kg-1) or pirenzepine (10 mg.kg-1) was shown to significantly decrease the morphine withdrawal symptoms in rats. The levels of m1, m2, m3 and m5 in spinal cord were increased by pretreatment with pirenzepine and the levels of m2, m3 and m4 in spinal cord were increased by pretreatment with scopolamine.</p><p><b>CONCLUSION</b>The adaptive expression of muscarinic receptors at spinal and supraspinal levels play important role in mediating morphine dependence and withdrawal in rats.</p>

Expression of ? and ? opiate receptor in spinal cord andbrainstem during morphine withdrawal in rats / 中国临床药理学与治疗学

Aim To observe the gene expression of ? and ? opiate receptor in spinal cord and brainstem,and the effects of muscarinic receptor antagonist, NMDA receptor antagonists and inhibitor of nitric oxide synthase on the expression of these genes during morphine withdrawal in rats. Methods The mRNA levels of ? and ? opiate receptor mRNA were assayed by reverse transcription polymerase chain reaction (RT_PCR) with the beta_actin mRNA as an internal control. Results The ? opiate receptor mRNA levels were increased significantly in spinal cord and brainstem during morphine dependence, and decreased after injection of naloxone during morphine withdrawal in rats. The ? opiate receptor mRNA levels in spinal cord and brainstem were changed conversely compared with the ? opiate receptor mRNA levels during morphine dependence and withdrawal. The ? and ? opiate receptor mRNA levels in spinal cord and brainstem were decreased by administration of either Rp_cAMPs or calyculin A while these levels were not changed by Sp_cAMPs at half hour before injection of naloxone in morphine dependent rats. Administration of l_N_nitric arginine methylester(10 mg?kg-1) resulted in a decrease of ? opiate receptor and ? opiate receptor levels in spinal cord , and ? opiate receptor levels in spinal cord and ? opiate receptor levels in brainstem were dedcreased by pretreatment with methyl_scopolamine (0.5 mg?kg-1) during morphine withdrawal. However, the ? and ? opiate receptor levels in both spinal cord and brainstem were not different from those of morphine withdrawal rats pretreated with either MK801 (0.125 mg?kg-1) or pirezenpine(10 mg?kg-1). In adddition, ?_actin mRNA levels were not different in each group.Conclusion The expression of ? opiate receptor and ? opiate receptor mRNA plays an important role in mediating the process of morphine dependence and withdrawal, and the expression of ? opiate receptor and ? opiate receptor mRNA in spinal cord and brainstem could be inhibited by block of muscarinic receptor or inhibition of nitric oxide production.