A combined injectable contraceptive improves plasma redox status and does not induce vascular changes in female rats

Abstract

This study aimed to investigate the effects of the combined injectable contraceptive (CIC) containing estradiol valerate (EV) and norethisterone enanthate (NET-EN) on aorta function and morphology, as well as on redox status, of female Wistar rats. Female rats (9-10 weeks of age) received intramuscular injections of CIC (0.1 mg EV plus 1 mg NET-EN) or castor oil (control group, CTL) for 8 weeks, once a week. Food intake, body weight and systolic blood pressure were measured during the treatment period. Thoracic aortic segments were prepared for isometric tension recording and morphological analysis. Redox status was evaluated by total oxidant status (TOS) and lipid peroxidation (LP) on plasma and reduced glutathione (GSH) on whole blood. CIC group presented lower food intake and lower total weight gain compared to CTL group. There was no change in systolic blood pressure, vascular response of aorta to phenylephrine and acetylcholine and aorta thickness. Plasma TOS and LP values were reduced in CIC group, although GSH was not altered. It was shown that the long-term treatment with the CIC containing EV plus NET-EN does not induce endothelial dysfunction and histomorphometric changes of vascular wall, as well as improves redox status on female Wistar rats.

Key words
combined injectable contraceptive; estradiol valerate; norethisterone enanthate; oxidative stress; vascular morphology; vascular reactivity