Patierno Simona, Zellalem Wubanche, Ho Anthony, Parsons Chris G, Lloyd K C Kent, Tonini Marcello, Sternini Catia
CURE Digestive Diseases Research Center, Digestive Diseases Division, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, 90073, USA.
Gastroenterology. 2005 Jun;128(7):2009-19. doi: 10.1053/j.gastro.2005.03.042.
BACKGROUND & AIMS: We tested the hypothesis that N-methyl-D-aspartate (NMDA) receptors mediate surgery-induced opioid release in enteric neurons.
We used mu opioid receptor (muOR) internalization as a measure of opioid release with immunohistochemistry and confocal microscopy. MuOR internalization was quantified in enteric neurons from nondenervated and denervated ileal segments of guinea pig after abdominal laparotomy with and without pretreatment with NMDA-receptor antagonists acting at different recognition sites (+)-5-methyl-10,11-dihydro-5H-dibenzo [a,b] cyclohepten-5,10-imine (MK-801) or (D) 2-amino-5-phosphopenoic acid (AP-5) at .5, 1 mg/kg; 8-chloro-4-hydroxy-1-oxo-1,2-dihydropyridazinol [4,5-]quinoline-5-oxide choline (MRZ 2/576) or 8-chloro-1,4-dioxo-1,2,3,4-tetrahydropyridazinol [4,5-]quinoline choline salt (MRZ 2/596) at .3, 1 mg/kg, or with an antagonist for the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, 6-cyano-7-nitroquinoxaline-2,3-dione (1, 3 mg/kg). To determine whether NMDA stimulation induces opioid release, (1) ilea were exposed to NMDA (100 micromol/L) and D-serine (10 micromol/L) with or without the antagonist MK-801 or AP-5 (50 micromol/L); and (2) neuromuscular preparations of the ileum were stimulated electrically (20 Hz, 20 min) with or without MK-801 or AP-5 (50 micromol/L).
MuOR endocytosis induced by abdominal laparotomy was inhibited significantly by NMDA-receptor antagonists in nondenervated and denervated ileal segments, but not by the AMPA-receptor antagonist. MuOR endocytosis in neurons exposed to NMDA or electrical stimulation was prevented by NMDA-R antagonists.
Abdominal laparotomy evokes local release of glutamate that results in endogenous opioid release through the activation of peripheral NMDA receptors. This suggests an interaction between the glutamatergic and opioid systems in response to the noxious and perhaps mechanosensory stimulation of surgery.
我们检验了N-甲基-D-天冬氨酸（NMDA）受体介导手术诱导肠神经元中阿片类物质释放的假说。
我们采用μ阿片受体（μOR）内化作为阿片类物质释放的指标，运用免疫组织化学和共聚焦显微镜技术进行检测。在豚鼠腹部剖腹术后，分别于有无使用作用于不同识别位点的NMDA受体拮抗剂（+）-5-甲基-10,11-二氢-5H-二苯并[a,b]环庚烯-5,10-亚胺（MK-801）或（D）-2-氨基-5-磷酸戊酸（AP-5）（剂量为0.5、1mg/kg）、8-氯-4-羟基-1-氧代-1,2-二氢哒嗪并[4,5-]喹啉-5-氧化物胆碱（MRZ 2/576）或8-氯-1,4-二氧代-1,2,3,4-四氢哒嗪并[4,5-]喹啉胆碱盐（MRZ 2/596）（剂量为0.3、1mg/kg）预处理的情况下，对非去神经和去神经回肠段的肠神经元中μOR内化进行定量分析；或使用α-氨基-3-羟基-5-甲基-4-异恶唑丙酸（AMPA）受体拮抗剂6-氰基-7-硝基喹喔啉-2,3-二酮（剂量为1、3mg/kg）进行预处理。为确定NMDA刺激是否诱导阿片类物质释放，（1）将回肠暴露于NMDA（100μmol/L）和D-丝氨酸（10μmol/L）中，同时加入或不加入拮抗剂MK-801或AP-5（50μmol/L）；（2）在加入或不加入MK-801或AP-5（50μmol/L）的情况下，对回肠的神经肌肉制剂进行电刺激（20Hz，20分钟）。
NMDA受体拮抗剂可显著抑制腹部剖腹术在非去神经和去神经回肠段诱导的μOR内吞作用，但AMPA受体拮抗剂无此作用。NMDA受体拮抗剂可阻止暴露于NMDA或电刺激的神经元中的μOR内吞作用。
腹部剖腹术引起谷氨酸局部释放，通过激活外周NMDA受体导致内源性阿片类物质释放。这提示在对手术的有害及可能的机械性感觉刺激的反应中，谷氨酸能系统与阿片类物质系统之间存在相互作用。
