The acyl amides are a family of endogenous lipids that act as potent modulators of pain and inflammation. The best characterized members of this family are the arachidonoyl amides, which includes N-arachidonoyl ethanolamide (AEA; anandamide). N-palmitoyl glycine (PalGly) contains an 18-carbon saturated fatty acid that is amide-linked to glycine and is structurally similar to the phospholipid-derived N-acyl ethanolamines. Endogenously produced in rat skin and spinal cord, PalGly is present in 100-fold greater amounts in skin and 3-fold greater in brain compared to AEA. Injection of 0.43 ?g PalGly in rat hindpaw inhibits heat-induced firing of nociceptive neurons in rat dorsal horn. PalGly treatment induces transient calcium influx in native dorsal root ganglion (DRG) cells and in the PTX-sensitive, DRG-like cell line F-11 (EC50 = 5.5 ?M).