Physiology and Pharmacology
Physiol Pharmacol
Medical Sciences
http://ppj.phypha.ir
32
journal32
24765236
24765244
10.61186/phypha
(previous ISSN: 17350581)
en
jalali
1395
5
1
gregorian
2016
8
1
20
3
online
1
fulltext
en
Morphine-induced analgesic tolerance is associated with alteration of protein kinase Cγ and transient receptor potential vanilloid type 1 genes expression in rat lumbosacral cord and midbrain
Pain and addiction
Neurophysiology/Pharmacology
Experimental research article
Experimental research article
<p dir="ltr" style="text-align: justify;"><span style="font-size: 12px;"><b>Introduction: </b><font face="Arial,Arial"><font face="Arial,Arial">Transient receptor potential vanilloid type 1 (TRPV1) and protein kinase Cγ (PKCγ) are involved in sensitization/desensitization to noxious stimuli. We aimed to examine the gene expression levels of TRPV1 and PKCγ in rat lumbosacral cord and midbrain on days 1, 4 and 8 of induction of morphine analgesic tolerance. </font></font></span><span style="font-size: 12px;"><b>Methods: </b><font face="Arial,Arial"><font face="Arial,Arial">Two groups of male Wistar rats received twice daily saline (1 ml/kg) or morphine (10 mg/kg) for eight days and were monitored for analgesic tolerance with a hotplate test on days 1, 4 and 8 of the injections. Six independent groups in three sets were also treated with saline or morphine, decapitated on days 1, 4 or 8 of the schedule, respectively and their lumbosacral cord and midbrain were dissected. </font></font></span><span style="font-size: 12px;"><b>Results: </b><font face="Arial,Arial"><font face="Arial,Arial">The result of the hotplate test revealed induction of analgesic tolerance on days 4 and 8 of morphine injections. The TRPV1 gene expression in the lumbosacral cord was significantly increased only on day 4 of morphine injections, but the PKCγ gene expression remained with no significant changes on days 1, 4 and 8. In the midbrain, the TRPV1 gene expression was significantly increased only on day 1; however, the PKCγ gene expression was significantly increased on days 4 and 8 of morphine injections. </font></font></span><span style="font-size: 12px;"><b>Conclusion: </b><font face="Arial,Arial"><font face="Arial,Arial">It can be concluded that the TRPV1 gene expression changes in the lumbosacral cord and midbrain is associated with early phase of morphine-induced analgesic tolerance but the PKCγ gene expression is altered only in midbrain at the later phase of process. </font></font></span></p>
Morphine, Analgesic tolerance, Gene expression, Spinal cord, Midbrain, TRPV1, PKCγ
147
156
http://ppj.phypha.ir/browse.php?a_code=A-10-916-1&slc_lang=en&sid=1
Shamseddin
Ahmadi
sh.ahmadi@uok.ac.ir
3200319475328460016684
3200319475328460016684
Yes
Department of Biological Science and Biotechnology, Faculty of Science, University of Kurdistan, Sanandaj, Iran
Neda
Parvini
n.parvini@uok.ac.ir
3200319475328460016685
3200319475328460016685
No
Department of Biological Science and Biotechnology, Faculty of Science, University of Kurdistan, Sanandaj, Iran