CONTRACEPTIVE STEROIDS INCREASE ERYTHROCYTE LIPID-PEROXIDATION IN FEMALE RATS

In order to investigate the effects of contraceptive steroid combinati ons on lipid peroxidation in the erythrocyte membranes, adult female r ats were divided into 2 groups for short- and long-term investigations ; each group was then subdivided into 5 subgroups according to orally given low and high doses of EE/NEA (ethinyl estradiol/norethisterone a cetate) and EE/LNG (ethinyl estradiol/levonorgestrel) combinations and control group. Since EE was included in each combination, the groups were named according to the progestin (NEA, LNG) components. At the en d of the experiment periods, lipid peroxidation in the erythrocyte mem branes from rats was measured. When compared to the controls, except l ow-dose LNG groups, lipid peroxidation levels were increased in all st udy groups. It was seen that the effect of NEA and LNG combinations on lipid peroxidation was not time-, but dose-dependent. When these comb inations were compared to each other, different effects of NEA and LNG on lipid peroxidation were not detected in the experiment period. As a result, the increased lipid peroxidation following the administratio n of contraceptive steroid combinations is a very important finding th at should be taken into account, in addition to the effects of these s teroids on lipid and lipoprotein metabolism.