Figure 4. Analgesic response to clonidine 150 micro gram *symbol* kg sup -1 intraperitoneally in rats various time intervals after treatment with N-ethoxycarbonyl-2-ethoxy-1, 2-dihydroquinoline (EEDQ). Separate groups of rats were administered EEDQ. 0, 0.1, 0.2, and 0.3 micro gram *symbol* kg sup -1 subcutaneously 1, 3, and 8 days later, their analgesic response to clonidine 150 micro gram *symbol* kg sup -1 intraperitoneally was tested. Data are expressed as a percentage of the maximal possible effect. Data were analyzed by analysis of variance and post hoc Scheffe test where appropriate. *P < 0.05, n = 7 or 8 per group.