【摘要】 目的探讨异丙酚对大鼠内脏抗伤害作用与中枢γ-氨基丁酸受体A(BABA_A)的关系。方法49只雄性SD大鼠,体重180-240 g,随机均分为7组:腹腔异丙酚10 mg／kg体重组(P i．p．)、侧脑室荷包牡丹碱0．25 μg组(Bic i．c．v．)、脊髓蛛网膜下腔荷包牡丹碱0．25μg(Bic i．t．)、侧脑室与脊髓蛛网膜下腔荷包牡丹碱各0．125μg组(Bic i．c．v．／i．t．)、侧脑室预注荷包牡丹碱0．25 μg+腹腔异丙酚10 mg／kg体重组(Bic i．c．v．+P i．p．)、脊髓蛛网膜下腔预注荷包牡丹碱0．25μg+ 腹腔异丙酚10mg／kg体重组(Bici．t．+Pi．p．)、侧脑室与脊髓蛛网膜下腔预注荷包牡丹碱各0．125 μg+腹腔异丙酚10 mg/kg体重组(Bic i．c．v．／i．t．+P i．p．)。侧脑室或／和脊髓蛛网膜下腔预注荷包牡丹碱后10 min腹腔给药。采用结直肠扩张内脏痛模型,以腹壁明显收缩变平的最小扩张压力值为痛阈,观察给药前及给药后各时间点的大鼠痛阈变化。结果腹腔注射异丙酚10 mg/kg体重,5 min后结直肠扩张痛阈显著提高(P<0．05．P<0．01),10～15 min达高峰,持续20 min;侧脑室、脊髓蛛网膜下腔或侧脑室+脊髓蛛网膜下腔预注荷包牡丹碱后结直肠扩张痛阈均无明显变化 (P>0．05);侧脑室、脊髓蛛网膜下腔或侧脑室+脊髓蛛网膜下腔预注荷包牡丹碱后10min腹腔注射异丙酚10mg／kg体重,3组给药后5～20min内结直肠扩张痛阈也均有提高,但其增高值均明显低于P i．p．组(P<0．05,P<0．01);且这3组之间最大镇痛效应差异无统计学意义(P>0．05)。结论侧脑室、脊髓蛛网膜下腔、侧脑室+脊髓蛛网膜下腔预注荷包牡丹碱,均可部分拮抗异丙酚的内脏抗伤害作用,因而异丙酚的内脏抗伤害作用受脊髓与脊髓上中枢γ-氨基丁酸A受体介导。更多还原

【Abstract】 To investigate the antinociceptive effect on visceral pain of propofol and its relation with BABA_A receptor in central nervous system. Methods Visceral pain model by colorectal distensions was established in male SD rats weighing 180-240 g (n = 49). Rats were randomly divided into 7 groups (n = 7 in every group). After implanting catheters in intracerebroventricular and/or intrathecal 5-7 days, rats were injected with propofol 10 mg/kg i.p. (group P i.p.), or with bicuculline 0.25 μg i.c. v.and/or i. t. (group Bic i.c. v.,group Bic i. t., group Bic i.c. v./i. t. ) ;or with propofol 10 mg/kg i.p. followed by injection of bicuculline 0.25 μg i. c. v. and/or i. t. (group Bic i. c. v. + P i. p., group Bic i. t. + P i. p, group Bic i.c. v./ i. t. + P i. p. ). Propofol was administered i.p. 10 min after injection of Bic into center. The minimal pressure in balloon during colorectal distensions necessary for the abdomen flatting was taken as the threshold. The antinociceptive effect of propofol was assessed by the threshold of visceral pain before and after injection of drugs. Results Propofol at doses of 10 mg/kg significantly increased the threshold of colorectal distensions after i. p. 5 min (P<0.05), its peak time was 10-15 min, lasting 20 min. The threshold of colorectal distensions had no significant difference before and after injection of Bic into i. c. v. and/or i. t.. Propofol i.p. could also significantly increase the threshold of colorectal distensions 10 min after injection of Bic i. c. v. and/or i. t., which was significantly lower than that of the group of propofol i.p. (P<0.01) .Conclusion Propofol has an antinociceptive effect on mechanical visceral pain induced by colorectal distensions, which can be inhibited partly by central injection of Bic. Therefore, the visceral antinociceptive effect of propofol is related to BABAA receptor, not only in spine center, but also in superspine center.更多还原