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>

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.

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.

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.