Effect of agmatine on morphine analgesia and tolerance in a rat model of neuropathic pain / 中华麻醉学杂志

ABSTRACT

25% signified analgesic effect. Part II (the effect of agmatine on analgesic effect of morphine). Fifty-six animals with neuropathic pain were randomly divided into 4 groups ( n = 14 each) . Each group received NS or agmatine 20, 40 or 60 mg? kg-1 . 30 min later each group received either NS or morphine 1 mg?kg-1(n=7 each). PWT was measured and PMAP was calculated Part III (the effects of agmatine on the development of morphine tolerance). Morphine tolerance was incuced by morphine 10 mg?kg-1, 3 times a day for 5 days. Thirty-five animals with neuropathic pain were randomly divided into 5 groups ( n = 7 each) group A received NS group B received NS + morphine; grouop C, D, E received agmatine 5, 10, 20 mg ? kg-1 + morphine 3 times a day for 5 days. PWT was measured on the 5th day and PMAP was calculated. Results PMAP of agmatine (40, 60 mg?kg-1 i.p.) and morphine (1 mg?kg-1 s.c.) were lower than 40% . Agmatine 60 mg?kg-1 increased the PMAP of morphine 1 mg?kg-1 to 84% compared with 34% for morphine alone (P