Skip to main content
. 2019 Oct 15;22(11):735–745. doi: 10.1093/ijnp/pyz054

Figure 3.

Figure 3.

Dose response and time course effects of CYM-52220 and CYM-52288 on U50,488-induced analgesia in the warm water tail flick assay (TFA). (a) CYM-52220 [n = 12 (0.0 mg/kg), 12 (3.0 mg/kg), 13 (6.0 mg/kg), 16 (8.0 mg/kg), 9 (10 mg/kg), and 6 (30.0 mg/kg)] was administered p.o. 1-hour prior to injection of U50,488 (30 mg/kg, IP), and TFA latencies were determined 1-hour after U50,488 administration. (b) Based on the CYM-52220 dose response, nonlinear regression was used to determine the AD80 dose, which was then used to test the ability of CYM-52220 to attenuate U50,488-induced analgesia when administered 1 hour (n = 14), 2 hours (n = 14), 4 hours (n = 14), 8 hours (n = 14), and 24 hours (n = 8) prior to the TFA test. CYM-52220 vehicle control groups were included for each time point, but similar to data shown in Figure 2C there was no significant difference in tail flick latencies at any vehicle time point, so the values were combined (total n = 60). CYM-52220 (6.0 mg/kg, p.o.) significantly reduced U50,488-induced increases in TFA latency when administered 1, 2, 4 (but not 8), or 24 hours before the TFA test. (c) CYM-52288 [n = 16 (0.0 mg/kg), 17 (1.0 mg/kg), 16 (1.8 mg/kg), 16 (2.4 mg/kg), 19 (3.0 mg/kg), and 16 (10.0 mg/kg)] was administered p.o. 1 hour prior to injection of U50,488 (30 mg/kg, IP), and TFA latencies were determined 1 hour after U50,488 administration. *P < .05, **P < .01 compared with the 0.0-mg/kg dose. (d) Based on the CYM-52288 dose response, nonlinear regression was used to determine the AD80 dose, which was then used to test the ability of CYM-52288 to attenuate U50,488-induced analgesia when administered 1 hour (n = 13), 2 hours (n = 11), 4 hours (n = 9), 8 hours (n = 12), and 24 hours (n = 10) prior to the TFA test. CYM-52288 vehicle control groups were included for each time point, but similar to data shown in Figure 2C, there was no significant difference in tail flick latencies at any vehicle time point, so the values were combined (total n = 20). CYM-52288 (3.2 mg/kg, p.o.) significantly reduced U50,488-induced increases in TFA latency when administered 1, 2, and 4 (but not 8) hours before the TFA test. There was a strong trend (P = .06) for CYM-52288 to reduce U50,488-induced increases in TFA latency when administered 24 hours before testing. *P < .05, **P < .01 compared with vehicle.