mRNA expression of muscarinic receptors in spinal cord and brainstem in morphine dependent rats.
- Author:
Wen-hua ZHOU
1
;
Hui-fen LIU
;
Jun GU
;
Xiao-hu XIE
;
Shuai-en TANG
;
Guo-dong YANG
;
Qi-xia WU
Author Information
- Publication Type:Journal Article
- MeSH: Animals; Brain Stem; drug effects; metabolism; Gene Expression; drug effects; Male; Morphine; toxicity; Morphine Dependence; metabolism; RNA, Messenger; biosynthesis; drug effects; Rats; Rats, Sprague-Dawley; Receptors, Muscarinic; biosynthesis; classification; genetics; Spinal Cord; drug effects; metabolism; Substance Withdrawal Syndrome; metabolism
- From: Acta Pharmaceutica Sinica 2002;37(8):611-615
- CountryChina
- Language:Chinese
-
Abstract:
AIMTo observe mRNA expression of muscarinic acetylcholine receptors in spinal cord and brainstem in morphine dependent or withdrawal rats.
METHODSThe mRNA expression level of m1, m2, m3, m4 and m5 were determined by RT-PCR, the beta-actin mRNA expression was used as internal control.
RESULTSThe mRNA level of m1, m2, m3, m4 and m5 in spinal cord and m1 and m2 in brainstem were increased significantly during morphine dependence, and the levels of m1, m2, m3 and m4 in spinal cord and m1 in brainstem were decreased 1 h after the injection of naloxone (4 mg.kg-1, i.p.) in morphine dependent rats. Either scopolamine (0.5 mg.kg-1) or pirenzepine (10 mg.kg-1) was shown to significantly decrease the morphine withdrawal symptoms in rats. The levels of m1, m2, m3 and m5 in spinal cord were increased by pretreatment with pirenzepine and the levels of m2, m3 and m4 in spinal cord were increased by pretreatment with scopolamine.
CONCLUSIONThe adaptive expression of muscarinic receptors at spinal and supraspinal levels play important role in mediating morphine dependence and withdrawal in rats.
