Prostaglandins, (prostanoic acid derivatives) - produce a wide range of physiological activities (beneficial and/or pathological); such as smooth muscle stimulation, arteries dilation, blood pressure lowering, platelet aggregation/inhibition,etc. These compounds can also generate a variety of pathological conditions: dysmenorrhea, inflammatory reactions, kidney failure, autonomic neurotransmision ,etc.

These compounds have been proposed as radiation protective agents. No convincing rationale for this decision has been presented. This review will start with the most optimistic approach and then continue with the more realistic experimental data:

OPTIMIST

[1] 21 May l987 {02204} George W. Irving, III Colonel, USAF, BSC
Director, Armed Forces Radiobiology Research Institute [AFRRI].

"...several factors have been purified from tissues or made by new biotechnology procedures. These and other recent development in the field look extremely promising...."

...it is most expeditious for us to concentrate our efforts on purified agents, other that spleen factor, that appear to be considerably well advanced, thus offering higher near-term payoff."

[2] 13 January 1999 {5001} Robert R. Eng, Col., USA, MSC
Director, Armed Forces Radiobiology Research Institute [AFRRI].

"Today at the Armed Forces Radiobiology Research Institute our investigators study the prophylactic and therapeutic potential of several naturally produced and well defined biological response modifiers. ........Cytokines and prostaglandins have shown promising results for mitigating the harmful effects of ionizing radiation. Considering the excellent progress being made with these compounds whose chemical structures and mechanisms of action are so well defined....."

REALIST

Walden, T.L., Patchen, M., and Snyder, S.L. (AFRRI). 16, 16-Dimethyl Prostaglandin E2 increases Survival in Mice following Irradiation. Radiat Res. 109, 440 - 448 (1987)

"..... The mechanism(s) by which prostaglandins induce radio-and cytoprotection are not understood. The complexity of prostaglandin involvement... Ten micrograms administered 5 min prior to receiving a lethal dose of Gy provides 90% survival but only 10% survival if administered 30 mins prior to irradiation."

Hanson,W.R., and Ainsworth, E.J., 16,16-Dimethyl Prostaglandin E2 Induces Radioprotection in Murine Intestinal and Hematopoietic Stem Cells. Radiat.Res. 103, 196 - 203 (1985 ).


"......PGP-induced cytoprotection of the gastrointestinal mucosa from a variety of injurious agents suggested that PGs may play some role in the expression of intestinal injury and subsequent recovery after ionizing radiation..... A large number of human tumors secrete a variety of PGs Our results suggest that these tumors may be, in part, protected from radiation injury."


Comment: No substantial paper has been published indicating any degree of success for this program.