1,3-Di-o-tolylguanidine (DTG) differentially affects acute and tonic formalin pain: antagonism by rimcazole.

Abstract

The role of the sigma receptor in prolonged pain was examined by assessing the effects of 1,3,di-o-tolylguanidine (DTG), a selective sigma receptor ligand, on the formalin test in mice. Formalin injected subcutaneously into the hindpaw produces a biphasic pain response: an acute phase of short duration followed by a longer-lasting tonic phase. DTG (10 mg/kg, i.p.) potently reduced pain behavior in the acute phase but increased pain behavior in the tonic phase. Rimcazole (5 and 10 mg/kg, i.p.), a selective sigma receptor antagonist, blocked both the DTG-induced decrease and increase in pain behavior observed in the acute and tonic phases, respectively. These data support previous findings indicating a modulatory role for the sigma receptor in nociceptive processes, and suggest that this receptor differentially modulates acute vs. tonic pain.

• Authors: B Kest, J S Mogil, W F Sternberg, R N Pechnick, J C Liebeskind
• Journal: Pharmacology, biochemistry, and behavior (Pharmacol Biochem Behav) Vol. 52 Issue 1 Pg. 175-8 (Sep 1995) ISSN: 0091-3057 [Print] United States
• PMID: 7501662 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Carbazoles
• Guanidines
• Receptors, sigma
• Formaldehyde
• rimcazole
• 1,3-ditolylguanidine

Topics

• Animals
• Carbazoles (pharmacology)
• Formaldehyde
• Guanidines (antagonists & inhibitors, pharmacology)
• Male
• Mice
• Pain Measurement (drug effects)
• Receptors, sigma (antagonists & inhibitors)