Fig. 2.
Thermal escape latency with no infusion or chronic infusion of NaCl or morphine sulfate (MS) with polyethylene catheters. (A) Thermal escape latencies (mean ± SD) in guinea pigs plotted versus time for groups implanted with intrathecal (IT) polyethylene catheters and receiving chronic infusion of 0.9% NaCl (NaCl), MS (0.125, 1.25, 8.0, or 12.5 μg/h) or no infusion. Results were analyzed using two-way repeated measures ANOVA and show significance (interaction, not significant; treatment, P = 0.0197; and time P = 0.0006). Bonferroni post hoc tests comparing to baseline were without statistical significance. (B) Scatter plot showing area under the curve (AUC; baseline, 7 days) plotted with individual animals by treatment group. One-way ANOVA by treatment and Tukey multiple comparisons post hoc test were without statistical significance across treatment groups (P = 0.8812).