Skip to main content
. Author manuscript; available in PMC: 2016 Apr 1.
Published in final edited form as: Eur J Neurosci. 2015 Jan 9;41(7):899–905. doi: 10.1111/ejn.12829

Figure 3. Determination of NTI dose necessary to prevent morphine analgesic tolerance in inflamed rats.

Figure 3

CFA inflamed rats were pretreated as illustrated in Fig. 1 with NTI (0.003 to 0.3 mg/kg) as a DOP antagonist. Twelve hours after the last pretreatment injection (saline followed 15 min later by saline (□), saline followed 15 min later by morphine (■) or three different doses of NTI (■)), the analgesic effect of a challenging dose of morphine (3 mg/kg) was measured using the Hargreaves test. Results are expressed as area under curve obtained between 0 and 60 min after morphine challenge dose (Y baseline set for each animal according to its latency to paw withdrawal after inflammation). (N = 9–15 rats), *, p<0.05 and ***, p<0.001 when groups were compared to Saline/Morphine group. NTI at 0.03 mg/kg is sufficient to prevent morphine analgesic tolerance.