Yien H W, Chan J Y, Tsai H F, Lee T Y, Chan S H
Department of Anesthesiology, National Yang-Ming Medical College, Taipei, Taiwan, ROC.
Neurosci Lett. 1993 Sep 3;159(1-2):9-12. doi: 10.1016/0304-3940(93)90785-j.
We evaluated the participation of nucleus reticularis gigantocellularis (NRGC), a medullary nucleus that plays an important role in the regulation of nociceptive processes, in the antinociceptive effect of angiotensin III (AIII), a biologically active peptide of the renin-angiotensin system. Adult, male Sprague-Dawley rats anesthetized with pentobarbital sodium (40 mg/kg, i.p., with 10 mg/kg/h i.v. infusion supplement) were used. Bilateral, site-specific microinjection of AIII (80 or 160 pmol) into the NRGC produced a dose-related increase in the latency of tail-flick response to noxious thermal stimuli (50 degrees C hot water). Such an antinociceptive action of AIII was blocked by concomitant administration of the AIII receptor antagonist, Ile7-angiotensin III (Ile7-AIII, 10 nmol). At the neuronal level, microiontophoretic application of AIII suppressed, Ile7-AIII reversibly, the responsiveness of nociception-related neurons in the NRGC to tail-clamping. These results demonstrated that central AIII may elicit antinociception via a process that may at least take place at the NRGC.
我们评估了巨细胞网状核（NRGC，髓质中的一个核团，在伤害性感受过程的调节中起重要作用）在血管紧张素III（AIII，肾素-血管紧张素系统的一种生物活性肽）的镇痛作用中的参与情况。使用戊巴比妥钠（40 mg/kg，腹腔注射，静脉输注补充剂量为10 mg/kg/h）麻醉的成年雄性Sprague-Dawley大鼠。将AIII（80或160 pmol）双侧、位点特异性微量注射到NRGC中，可使对有害热刺激（50摄氏度热水）的甩尾反应潜伏期呈剂量相关增加。AIII的这种镇痛作用可被同时给予的AIII受体拮抗剂Ile7-血管紧张素III（Ile7-AIII，10 nmol）阻断。在神经元水平，微量离子电渗法应用AIII可抑制、Ile7-AIII可可逆性抑制NRGC中伤害性感受相关神经元对夹尾刺激的反应性。这些结果表明，中枢AIII可能通过至少在NRGC发生的过程引发镇痛作用。
