Effect of sinomenine on morphine dependence in isolated guinea pig ileum.
OBJECTIVE
To investigate the effects of sinomenine on morphine withdrawal response and acetylchline (Ach)-induced contracture in isolated guinea pig ileum.


METHODS
The withdrawal contracture was elicited by subjecting isolated ileum incubated with morphine (3 micromol/L) at 37.5 degrees Celsius for 4 h to naloxone (1 micromol/L) treatment. Sinomenine (10, 50, 250 micromol/L) and nimodipine (Nim, 0.1 micromol/L) were administered 1 min before and after naloxone in morphine-dependent ilea bathed in Krebs solution containing morphine, to observe the changes in the withdrawal contracture of the ileum. The effect of sinomenine (10, 50, 250 micromol/L) on the contracture of untreated ileum in Krebs solution elicited by acetylcholine was also observed.


CONCLUSIONS
Naloxone-induced withdrawal contracture or acetylcholine-induced contracture of the ileum was significantly decreased in a dose-dependent manner, indicating that sinomenine can inhibit morphine withdrawal symptoms in guinea pigs.
Wang
Cai-yun
CY
Teaching and Research Section of Pharmacology and Medicinal Chemistry, Department of Traditional Chinese Medicine, First Military Medical University, Guangzhou 510515, China. caiyun221@263.net
Mo
Zhi-xian
ZX
Tu
Hong-hai
HH
D000818:Animals; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects*; D009019:Morphinans / Q000494:pharmacology*; D009020:Morphine / Q000494:pharmacology*; D009021:Morphine Dependence / Q000503:physiopathology*; D009119:Muscle Contraction / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology; D009553:Nimodipine / Q000494:pharmacology; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology
D009019:Morphinans; D009270:Naloxone; D009553:Nimodipine; C009271:sinomenine; D009020:Morphine