Delay of Morphine Tolerance by Palmitoylethanolamide

Table 1

TNF- levels in the spinal cord.

	TNF-α levels (pg/mg proteins)
	vehicle + vehicle	vehicle + morphine	PEA + morphine
	12.2 ± 3.2
Day 6		25.9 ± 3.8^*	30.7 ± 5.0^*
Day 11		32.7 ± 6.4^*	28.4 ± 3.0^*

In the dorsal horn of the spinal cord, TNF- levels were measured by ELISA on days 6 and 11. Rats were treated daily i.p. with 10 mg kg⁻¹ morphine and 30 mg kg⁻¹ PEA and compared with vehicle treatment. Each value represents the mean ± SEM of 6 rats per group, performed in 2 different experimental sets. ^*P < 0.05 versus vehicle + vehicle.