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Antinociceptive effects of maprotiline in a rat model of peripheral neuropathic pain: possible involvement of opioid system.

Banafshe HR, Hajhashemi V, Minaiyan M, Mesdaghinia A, Abed A - Iran J Basic Med Sci (2015)

Bottom Line: Systemic administration of maprotiline blocked heat hyperalgesia, cold allodynia and reduced mechanical allodynia.Also antihyperalgesic effect of maprotiline was reversed by pretreatment with naloxone.Our results suggest that maprotiline can be considered a potential therapeutic for the treatment of neuropathic pain, and the opioid system may be involved in the antihyperalgesic effects of maprotiline.

View Article: PubMed Central - PubMed

Affiliation: Physiology Research Center, Kashan University of Medical Sciences, Kashan, Iran ; Department of Pharmacology, School of Medicine, Kashan University of Medical Sciences, Kashan, Iran.

ABSTRACT

Objectives: Neuropathic pain remains a clinical problem and is poorly relieved by conventional analgesics. This study was designed to determine whether maprotiline administration was effective in alleviating symptoms of neuropathic pain and whether the antinociceptive effect of maprotiline mediated through the opioid system.

Materials and methods: Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve in rats, which resulted in thermal hyperalgesia, and mechanical and cold allodynia. Maprotiline (10, 20 and 40 mg/kg, IP) was administered on the 7(th) and 14(th) days after surgery. To study the role of the opioid system in the antinociceptive effects of maprotiline, maprotiline (20 mg/kg, IP) was administered in combination with naloxone (1 mg/kg, SC) on the 7(th) post-surgery day. Behavioral tests were done at 45 min after drug injections on the 7(th) and 14(th) days after surgery.

Results: Systemic administration of maprotiline blocked heat hyperalgesia, cold allodynia and reduced mechanical allodynia. Also antihyperalgesic effect of maprotiline was reversed by pretreatment with naloxone.

Conclusion: Our results suggest that maprotiline can be considered a potential therapeutic for the treatment of neuropathic pain, and the opioid system may be involved in the antihyperalgesic effects of maprotiline.

No MeSH data available.


Related in: MedlinePlus

Cold allodynia after CCI, (A) Time course of cold allodynia (B), Effect of maprotiline (10, 20 and 40 mg/kg IP) on cold allodynia The results are expressed as Mean ± SEM, ###P<<0.001 versus sham group, **P<<0.01 versus CCI group. n=6 in all groups
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Figure 1: Cold allodynia after CCI, (A) Time course of cold allodynia (B), Effect of maprotiline (10, 20 and 40 mg/kg IP) on cold allodynia The results are expressed as Mean ± SEM, ###P<<0.001 versus sham group, **P<<0.01 versus CCI group. n=6 in all groups

Mentions: As shown in Figure 1A the ipsilateral paw of nerve ligated animals became much more sensitive to acetone application (P<<0.001). Sham operation did not produce any alteration of the nociceptive response. Maprotiline (10, 20 and 40 mg/kg IP) treatment significantly reduced the withdrawal frequency in comparison with CCI group (P<<0.01) (Figure 1B).


Antinociceptive effects of maprotiline in a rat model of peripheral neuropathic pain: possible involvement of opioid system.

Banafshe HR, Hajhashemi V, Minaiyan M, Mesdaghinia A, Abed A - Iran J Basic Med Sci (2015)

Cold allodynia after CCI, (A) Time course of cold allodynia (B), Effect of maprotiline (10, 20 and 40 mg/kg IP) on cold allodynia The results are expressed as Mean ± SEM, ###P<<0.001 versus sham group, **P<<0.01 versus CCI group. n=6 in all groups
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4633457&req=5

Figure 1: Cold allodynia after CCI, (A) Time course of cold allodynia (B), Effect of maprotiline (10, 20 and 40 mg/kg IP) on cold allodynia The results are expressed as Mean ± SEM, ###P<<0.001 versus sham group, **P<<0.01 versus CCI group. n=6 in all groups
Mentions: As shown in Figure 1A the ipsilateral paw of nerve ligated animals became much more sensitive to acetone application (P<<0.001). Sham operation did not produce any alteration of the nociceptive response. Maprotiline (10, 20 and 40 mg/kg IP) treatment significantly reduced the withdrawal frequency in comparison with CCI group (P<<0.01) (Figure 1B).

Bottom Line: Systemic administration of maprotiline blocked heat hyperalgesia, cold allodynia and reduced mechanical allodynia.Also antihyperalgesic effect of maprotiline was reversed by pretreatment with naloxone.Our results suggest that maprotiline can be considered a potential therapeutic for the treatment of neuropathic pain, and the opioid system may be involved in the antihyperalgesic effects of maprotiline.

View Article: PubMed Central - PubMed

Affiliation: Physiology Research Center, Kashan University of Medical Sciences, Kashan, Iran ; Department of Pharmacology, School of Medicine, Kashan University of Medical Sciences, Kashan, Iran.

ABSTRACT

Objectives: Neuropathic pain remains a clinical problem and is poorly relieved by conventional analgesics. This study was designed to determine whether maprotiline administration was effective in alleviating symptoms of neuropathic pain and whether the antinociceptive effect of maprotiline mediated through the opioid system.

Materials and methods: Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve in rats, which resulted in thermal hyperalgesia, and mechanical and cold allodynia. Maprotiline (10, 20 and 40 mg/kg, IP) was administered on the 7(th) and 14(th) days after surgery. To study the role of the opioid system in the antinociceptive effects of maprotiline, maprotiline (20 mg/kg, IP) was administered in combination with naloxone (1 mg/kg, SC) on the 7(th) post-surgery day. Behavioral tests were done at 45 min after drug injections on the 7(th) and 14(th) days after surgery.

Results: Systemic administration of maprotiline blocked heat hyperalgesia, cold allodynia and reduced mechanical allodynia. Also antihyperalgesic effect of maprotiline was reversed by pretreatment with naloxone.

Conclusion: Our results suggest that maprotiline can be considered a potential therapeutic for the treatment of neuropathic pain, and the opioid system may be involved in the antihyperalgesic effects of maprotiline.

No MeSH data available.


Related in: MedlinePlus