Ono M, Satoh T
Department of Pharmacology and Toxicology, Tokyo College of Pharmacy, Japan.
Arzneimittelforschung. 1988 Jul;38(7):892-5.
The analgesic activity of lappaconitine, which is contained in the root of Aconitum sinomantanum Nakai, was examined after oral and subcutaneous administration to mice or rats by using methods for screening of analgesics, i.e., hot plate, tail immersion, tail pinch, tail pressure, acetic acid-induced writhing, bradykinin-induced flexor reflex of hind limb and Randall-Selitto methods. The results were compared with those for morphine, indometacin and acetylsalicylic acid (ASA). Analgesic activities of lappaconitine were greater than those of indometacin and ASA, but generally about 2 to 5 times less than those of morphine. However, in the rat tail immersion test, orally administered lappaconitine exhibited more potent analgesic activity than morphine; in this test, lappaconitine was almost equipotent when given orally and subcutaneously, whereas the potency of orally administered morphine was only one-twentieth of that of subcutaneously administered morphine. Like morphine, lappaconitine increased the pain threshold of the normal paw as well as that of the inflamed paw when tested by the Randall-Selitto method. The results show that lappaconitine has strong analgesic activity, and further suggest that the central nervous system may be involved in the action on the pain threshold.
采用热板法、尾浸法、尾捏法、尾压法、醋酸扭体法、缓激肽诱发后肢屈肌反射法和Randall-Selitto法等镇痛药筛选方法，对华北乌头（Aconitum sinomantanum Nakai）根中所含的拉帕乌头碱进行了小鼠和大鼠口服及皮下给药后的镇痛活性研究。将结果与吗啡、吲哚美辛和乙酰水杨酸（ASA）的结果进行了比较。拉帕乌头碱的镇痛活性大于吲哚美辛和ASA，但一般比吗啡低约2至5倍。然而，在大鼠尾浸法试验中，口服拉帕乌头碱的镇痛活性比吗啡更强；在该试验中，拉帕乌头碱口服和皮下给药时几乎等效，而口服吗啡的效力仅为皮下注射吗啡的二十分之一。与吗啡一样，用Randall-Selitto法测试时，拉帕乌头碱可提高正常爪和炎症爪的痛阈。结果表明，拉帕乌头碱具有较强的镇痛活性，并进一步提示中枢神经系统可能参与了对痛阈的作用。
