Figure 3.

The antinociceptive effect in the neuropathic pain model in relationship to the maximal length of the linkers. The effect was measured on days 7–14 after CCI surgical procedure by the von Frey (A) and cold plate (B) tests in CCI-exposed mice (5–8 animals per group). Red marks the compounds with long flexible linkers, while blue marks the analogs with short flexible linkers. The reference enkephalin analog is marked as an empty bar. The compounds for which no bar is visible exhibited little or no antinociceptive activity. The labels show the compound code and the linker present.