3-(2-hydroxy-4-(1-1-dimethylheptyl)phenyl)-4-(3-hydroxypropyl)cyclohexanol and Tinnitus

Previous studies in animals and humans have shown that, in some cases at least, anti-epileptic drugs can reduce the severity of tinnitus. Given that cannabinoid receptor agonists have been shown to exert anti-epileptic effects in some circumstances, we investigated whether two synthetic CB(1)/CB(2) receptor agonists, WIN55,212-2, and CP55,940, could inhibit the behavioural manifestations of salicylate-induced tinnitus in rats in a conditioned suppression task. We found that neither WIN55,212-2 (3.0 mg/kg s.c) nor CP55,940 (0.1 or 0.3 mg/kg s.c), significantly reduced conditioned behaviour associated with tinnitus. However, both 3 mg/kg WIN55,212-2 and 0.3 mg/kg CP55,940 did significantly increase tinnitus-related behaviour compared to the vehicle control groups. These results suggest that cannabinoid receptor agonists may not be useful in the treatment of salicylate-induced tinnitus and that at certain doses, they could actually exacerbate the condition.

Topics: Animals; Behavior, Animal; Benzoxazines; Conditioning, Operant; Cyclohexanols; Disease Models, Animal; Dose-Response Relationship, Drug; Male; Morpholines; Naphthalenes; Rats; Rats, Wistar; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Salicylic Acid; Tinnitus