Premium
Ameliorative effect of combined administration of inducible nitric oxide synthase inhibitor with cyclooxygenase‐2 inhibitors in neuropathic pain in rats
Author(s) -
Dudhgaonkar Shailesh P.,
Tandan Surendra K.,
Kumar Dinesh,
Naik Ajit K.,
Raviprakash V.
Publication year - 2007
Publication title -
european journal of pain
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.305
H-Index - 109
eISSN - 1532-2149
pISSN - 1090-3801
DOI - 10.1016/j.ejpain.2006.07.006
Subject(s) - meloxicam , rofecoxib , neuropathic pain , anesthesia , hyperalgesia , medicine , pharmacology , nitric oxide synthase , nociception , nitric oxide , cyclooxygenase , chemistry , receptor , biochemistry , enzyme
Objectives : The objective of this study was to examine the effects of rofecoxib, meloxicam, both cyclooxygenase‐2 (COX‐2) inhibitors and aminoguanidine hydrochloride, an inducible nitric oxide synthase (iNOS) inhibitor and their combinations in neuropathic pain in rats. Methods : Neuropathy was induced by chronic constriction injury (CCI) of right sciatic nerve under ketamine anesthesia in rats. Effect of ED 50 of aminoguanidine hydrochloride, rofecoxib and meloxicam administered orally was investigated using behavioral tests. Effect of combinations of aminoguanidine hydrochloride with rofecoxib and meloxicam was also investigated in neuropathic pain employing behavioral tests. Results : Behavioral tests, mechanical, thermal and cold stimuli confirmed the development of neuropathic pain after CCI. Aminoguanidine hydrochloride, rofecoxib and meloxicam when administered alone, produced significant increase in paw withdrawal threshold to mechanical stimuli at 6h in ipsilateral hind paw after CCI. Co‐administration of aminoguanidine hydrochloride (30mg/kg) with rofecoxib (1.31mg/kg) and meloxicam (1.34mg/kg) was also found to produce significant increase in paw withdrawal latencies to mechanical stimuli at 6h. Combined administration of aminoguanidine hydrochloride with meloxicam and rofecoxib produced significant rise in pain threshold for mechanical hyperalgesia in ipsilateral hind paw when compared with the groups treated with aminoguanidine hydrochloride, meloxicam and rofecoxib alone. Conclusion : Co‐administration of meloxicam and rofecoxib with aminoguanidine hydrochloride may be an alternative approach for the treatment of neuropathic pain.