Immunization against prostaglandins reduces delta 1-tetrahydrocannabinol-induced catalepsy in mice.

Immunization of mice with a thyroglobulin-prostaglandin E2 (PGE2) conjugate produced animals with measurable blood levels of anti-PGE2 antibodies. When these mice were challenged with delta 1-tetrahydrocannabinol (THC) (20 mg/kg), they showed a greatly diminished cataleptic response as compared with control animals. This observation further supports a hypothesis on the mechanism of action of THC in which eicosanoids, such as PGE2, are early mediators. Based on the likelihood that antibodies were not present in the central nervous system, it is suggested that the initial site of action of THC may be at one or more peripheral locations. The transport of peripheral PGE2 or other eicosanoids to the brain would result in the eventual manifestation of THC action at this site.