Iwasaki H, Ohmori H, Kobayashi I, Omote K, Kawamata M, Namiki A
Department of Anesthesiology, Sapporo Medical University, School of Medicine.
Masui. 1994 Nov;43(11):1648-52.
The analgesic effects of morphine, buprenorphine and pentazocine examined by behavioral responses to tail-flick (TF) and colorectal distension (CD) were studied in rats. Animals were randomly divided into three groups; morphine (M) groups of 4 mg.kg-1 (n = 7), buprenorphine (B) groups of 0.03 mg.kg-1 (n = 8), pentazocine (P) groups of 3 mg.kg-1 (n = 8). After determinations of TF and CD values, animals were administered each analgesic intraperitoneally, and both procedures were repeated every 5 minutes until 40 minutes. Three drugs produced an almost same degree of increase in pain threshold for TF; % maximum possible effects (%MPEs) were approximately 30%. Similar patterns of increase in pain thresholds for CD were observed in M and B groups; %MPEs were approximately 20%. In contrast, P groups showed a significant increase in thresholds for CD compared to M and B groups; 20 minutes after intraperitoneal administration of P, %MPE was approximately 50%. These results indicate that there are different antinociceptive effects to somatic and visceral stimuli between M, B and P, and suggest that selective opioid agonists modulate responses to different kinds of noxious stimuli.
通过对大鼠甩尾（TF）和结肠扩张（CD）行为反应来研究吗啡、丁丙诺啡和喷他佐辛的镇痛作用。动物被随机分为三组：吗啡（M）组，剂量为4mg·kg-1（n = 7）；丁丙诺啡（B）组，剂量为0.03mg·kg-1（n = 8）；喷他佐辛（P）组，剂量为3mg·kg-1（n = 8）。在测定TF和CD值后，给动物腹腔注射每种镇痛药，每隔5分钟重复这两种操作，直至40分钟。三种药物对TF的痛阈提高程度几乎相同；最大可能效应百分比（%MPEs）约为30%。在M组和B组中观察到CD痛阈升高的相似模式；%MPEs约为20%。相比之下，P组与M组和B组相比，CD阈值显著升高；腹腔注射P后20分钟，%MPE约为50%。这些结果表明，M、B和P对躯体和内脏刺激存在不同的抗伤害感受作用，并提示选择性阿片类激动剂可调节对不同类型有害刺激的反应。
