Caffeine Consumption Influences Lidocaine Action via Pain-Related Voltage-Gated Sodium Channels: An In Vivo Animal Study

Figure 3

Effects on thermal pain sensation test. The bar graph shows the time (seconds) from the application of the heat stimulus until the rat retracted its paw and was tested 0, 30, 60, and 90 minutes after the local (intraplantar) administration of lidocaine. The rats were divided into 4 subgroups (n = 8) as follows: control (Ctrl), receiving a local lidocaine injection (LIDO), habitual caffeine intake (CAF), and habitual caffeine intake and receiving a local lidocaine injection (CAF + LIDO). Caffeine was provided in the drinking water to the respective groups for 10-week (a), 11-week (b), and 12-week (c) periods. The statistical analysis was performed using a linear mixed model with repeated measures, and the main effects and time-specific differences were compared with adjustment using the Bonferroni test. Significant differences between the experimental groups are shown with the connecting bars and asterisks . Significant differences between the groups for the individual time points are indicated with small letters, where every two similar letters indicate a statistically significant difference between the two groups they represent for the specific time point.

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