Role of μ opioid receptor exon 7 in analgesic efficacy of endomorphin-2 in rats
10.3760/cma.j.issn.0254-1416.2014.11.018
- VernacularTitle:μ阿片受体外显子7在大鼠内啡肽-2镇痛效应中的作用
- Author:
Feng CHEN
;
Zongze ZHANG
;
Dongling CHEN
;
Yanlin WANG
- Publication Type:Journal Article
- Keywords:
Receptors,opioid,mu;
Exons;
Endorphins;
Analgesia
- From:
Chinese Journal of Anesthesiology
2014;34(11):1351-1353
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the role of μ opioid receptor exon 7 in the analgesic efficacy of endomorphin-2 in rats.Methods Twenty-four male Sprague-Dawley rats in which IT catheters were successfully implanted,weighing 220-260 g,were randomly divided into 3 groups (n =8 each) using a random number table:normal saline control group (group C),negative siRNA control group (group N-siRNA) andμ opioid receptor exon 7 siRNA group (group E7-siRNA).In C,N-siRNA and E7-siRNA groups,30μl saline solution,negative siRNA plasmid 20 μl + lipofectamine 2000 (10 μl),and μ opioid receptor siRNA plasmid 20μ1 + lipofectamine 2000 (10 μl) were intrathecally injected once a day for 3 consecutive days.The mechanical pain threshold was measured on 4th day (baseline).Endomorphin-2 10 μg was injected intrathecally at 1 h after measurement of the pain threshold.The mechanical pain threshold was measured at 5,20,40 and 60 min after endomorphin-2 injection,and the analgesic efficacy was calculated.Results There was no significant difference in the baseline pain threshold among the three groups.Compared with group C,no significant difference was found in the analgesic efficacy at each time point after endomorphin-2 injection in group N-siRNA,and the analgesic efficacy was significantly decreased at 5 and 20 min after endomorphin-2 injection in group E7-siRNA.Conclusion μ opioid receptor exon 7 is involved in the analgesic efficacy of endomorphin-2 in rats.
