Objectives: The aim of this study is to evaluate the relationship between plasma nitric oxide (NO) and β-endorphin levels in women using hormone replacement therapy (HRT) for 12 months. Material and Methods: Our study group was composed of 55 patients who were in at least their second postmenopausal year. Of the 55 patients, 25 were in the control group. All 30 women in the study group received 2 mg 17β-estradiol + 1 mg norethisterone acetate tablets daily for 12 months. Plasma NO and β-endorphin levels were measured both before and after the study period and possible relationships were analyzed. Results: There was a significant increase in both β-endorphin (p = 0.0001, 10.93 ± 2.25 vs. 14.85 ± 2.49) and NO (p = 0.0001, 19.79 ± 4.01 vs. 27.83 ± 10.27) levels measured after the study in the HRT group. A correlation was seen between the increments in β-endorphin and NO levels in the HRT group. Conclusion: Continuous combined HRT raises both plasma NO and β-endorphin levels and a close relationship was found between the two molecules after therapy. We postulate that the increment in these molecules may explain some of the beneficial effects of HRT on cognitive function and mood.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.