DIFFERENTIAL RADIOPROTECTIVE EFFECTS OF MISOPROSTOL IN DNA REPAIR-PROFICIENT AND REPAIR-DEFICIENT OR RADIOSENSITIVE CELL SYSTEMS

The protective effects of misoprostol (MP), an analogue of prostagland in E(1), on X-ray-induced chromosomal aberrations, were studied in nor mal or mutant Chinese hamster cell lines grown as spheroids in vitro a nd on cell-killing in stem-cell spermatogonia of a mutant (scid) mouse strain or its wild-type. The mutant hamster cell lines chosen for thi s purpose are known to be either hypersensitive to the killing effects of X-rays and/or deficient in the repair of DNA double-strand breaks. The scid mice are deficient in the repair of DNA double-strand breaks . The results show that MP manifests varying degrees of radioprotectio n in all these systems, but the magnitude of these effects in the muta nts is markedly reduced compared to their respective wild-type counter parts. These findings suggest a link between ionizing radiation sensit ivity, DNA double-strand break repair capability and MP-mediated radio protection.