Investigation into the effects of the photodecomposition of norethisterone by UV-B light on Salmonella typhimurium TA98 and the rat.

In view of the light-induced side-effects of the oral contraceptive pill and the development of injectable and subdermal contraceptive devices, the effects of norethisterone irradiated with UV-B light (280-320 nm) on the microorganism Salmonella typhimurium TA98 and male Wistar rats have been investigated. The observed cytotoxic effect of the photo-products on Salmonella typhimurium TA98 may in part be caused by the irreversible binding of steroid to protein from this bacterium, of which binding is in line with previous experiments. However, after intraperitoneal or percutaneous administration of 4-14C-norethisterone to rats, followed by irradiation with UV-B light, no significantly higher level of radioactivity was observed in blood, organ material of the skin, kidney or liver, on extraction or dialysis of the samples.