Hata T, Kita T, Itoh E, Oyama R, Kawabata A
Department of Pharmacology, Faculty of Pharmacy, Kinki University, Osaka, Japan.
Jpn J Pharmacol. 1988 Oct;48(2):165-73. doi: 10.1254/jjp.48.165.
Neurotropin, an extract from the inflamed skin of vaccinia virus-inoculated rabbits, has been observed clinically to be effective for treating pain in patients with lumbago, SMON and other neuropathies. In the present study, we examined the mechanism of the antinociceptive effect of neurotropin in mice in relation to administration routes, opioids, and noradrenergic or GABAergic drugs, by the tail pressure method. The antinociceptive effects of neurotropin were large when administered by the i.p. and intracisternal (i.cist.) routes, but comparatively small in the case of the intrathecal (i.th.) route. Neurotropin may thus act at the supraspinal level rather than on the spinal cord. The antinociceptive effect of neurotropin was not blocked by naloxone, and no cross-tolerance developed between neurotropin and morphine. The effect of neurotropin was blocked by phentolamine and reserpine, but not by atropine. Its effect was enhanced by GABA, muscimol, aminooxyacetic acid and diaminobutyric acid, but not by baclofen, and blocked by bicuculline methiodide. From these results, the antinociceptive action of neurotropin appears to be non-opioid in nature, and may possible be mediated by the noradrenergic and GABAergic systems, but unrelated to the cholinergic system.
神经妥乐平是从接种牛痘病毒的兔子发炎皮肤中提取的物质，临床观察发现它对治疗腰痛、亚急性脊髓视神经病（SMON）及其他神经病变患者的疼痛有效。在本研究中，我们通过尾压法研究了神经妥乐平对小鼠的镇痛作用机制，涉及给药途径、阿片类药物以及去甲肾上腺素能或γ-氨基丁酸能药物。神经妥乐平经腹腔注射和脑池内注射给药时镇痛作用较强，但鞘内注射时作用相对较弱。因此，神经妥乐平可能作用于脊髓以上水平而非脊髓。神经妥乐平的镇痛作用未被纳洛酮阻断，且与吗啡之间未产生交叉耐受性。神经妥乐平的作用被酚妥拉明和利血平阻断，但未被阿托品阻断。γ-氨基丁酸、蝇蕈醇、氨氧基乙酸和二氨基丁酸可增强其作用，但巴氯芬无此作用，且其作用被甲碘化荷包牡丹碱阻断。从这些结果来看，神经妥乐平的镇痛作用本质上似乎是非阿片类的，可能由去甲肾上腺素能和γ-氨基丁酸能系统介导，但与胆碱能系统无关。
