non-uniform presence in tissues or their ability to engage a receptor molecule [28]. However, these effects have a rapid onset beginning within 15 minutes following administration when first measurements were taken. Because sEH was not inhibited in these studies, the EFAs had a short duration of activity (<2 hours). Interestingly, while the direct administration of EFAs significantly reduced pain in these experiments the parent PUFAs at the same doses are devoid of effect. The PUFAs had to be administered at minimally 100 times higher doses to attain similar levels of pain reduction. Both the PUFAs and the EFAs had no effect on nociceptive thresholds of normal rats while they were highly efficacious in the induced pain model [29].
