Fig 6.

Rats were pretreated with dermorphin-saporin (derm-sap) (0.1 µg/µl) or saporin (sap) (0.1 µg/µl) 28 days before behavioral testing. Animals then received either SIF or IM, and withdrawal thresholds to stimuli applied to the face were determined at hourly intervals for 6 hrs. Rats pretreated with saporin and challenged with IM developed facial and hindpaw tactile allodynia (P < 0.05), as indicated by normalized maximal allodynic response. Pretreatment with derm-sap significantly * (P < 0.05) attenuated both facial and hindpaw IM-induced tactile allodynia. Behavioral responses were not altered by derm-sap in SIF rats or sap in SIF rats (data not shown).