Metabolism of anandamide, an endogenous cannabinoid receptor ligand, in porcine ocular tissues

Exp Eye Res. 1997 May;64(5):707-11. doi: 10.1006/exer.1996.0265.


Anandamide (arachidonylethanolamide) is an endogenous ligand for cannabinoid receptors, and exerts various cannabimimetic activities. Since cannabinoids and anandamide were pharmacologically active with the eye, we examined metabolism of anandamide in a variety of porcine ocular tissues. In the presence of ethanolamine, [14C]arachidonic acid was converted to [14C]anandamide by a homogenate of retina, choroid, iris, optic nerve and lacrimal gland with a specific enzyme activity of 1.9-4.2 nmol min-1 mg-1 protein at 37 degrees C. On the other hand, [14C]anandamide was hydrolysed to [14C]arachidonic acid by a homogenate of each tissue with a specific enzyme activity of 1.2-3.5 nmol min-1 mg-1 protein. Thus, both activities of anandamide synthase and hydrolase were found in these ocular tissues. As for the subcellular distribution, the two enzyme activities were mostly recovered in particulate fractions rather than the cytosol. With the retina microsome palmitic acid was converted to its ethanolamide at a lower rate than arachidonic acid, and palmitoylethanolamide was less active than anandamide as a substrate for the hydrolase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arachidonic Acids / metabolism*
  • Choroid / metabolism
  • Endocannabinoids
  • Eye / metabolism*
  • Hydrolases / metabolism
  • Iris / metabolism
  • Lacrimal Apparatus / metabolism
  • Lens, Crystalline / metabolism
  • Ligases / metabolism
  • Optic Nerve / metabolism
  • Polyunsaturated Alkamides
  • Retina / metabolism
  • Subcellular Fractions / enzymology
  • Substrate Specificity
  • Swine


  • Arachidonic Acids
  • Endocannabinoids
  • Polyunsaturated Alkamides
  • Hydrolases
  • Ligases
  • anandamide