The experimental evidence amply demonstrates that exogenous Pg is capable of inhibiting most immunological functions. The physiological role of Pgs in immune cell regulation, however, remains unresolved. This uncertainty arises from the fact that although Pgs are normally found in tissues in nanogram quantities or less, many experiments which demonstrate Pg mediated immune cell inhibition usually employ quantities at least one thousand- fold larger. In such experiments, the results, obviously reflect pharmacological rather than physiological effects. In view of the literature reviewed here, the following statements summarize the evidence which implicate Pg in a physiological role: 1. A. Pgs inhibit immune cell responsiveness. 2. B. Immune and non-immune cells secrete Pgs in response to various stimuli. 3. C. Immune cells possess receptors for Pgs. 4. D. Indomethacin enhances immune function in tumor-bearing and antigen-challenged mice. The recent indications that Pgs may mediate their effects through the cyclic endoperoxides and non-prostanoate metabolites may prove to be an important challenge to the many proposed roles of Pgs. At this time, no definitive evidence exists that compounds other than the classical Pgs are active in immune cell inhibition.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Pharmacology, Toxicology and Pharmaceutics(all)