Low dose hormonal therapy and reactive oxygen intermediates generation by neutrophils

Low dose HT is considered a standard in modern menopausal hormonal therapy. Lipid peroxidation, especially LDL cholesterol, is a well known effect of reactive oxygen intermediates (ROI) activity in organisms. Lipid peroxidation products have atherogenic activity, increasing ischaemic heart disease risk. Oestrogens used in HT have an antioxidative effect protecting the blood vessel wall.
Aim of study: Comparison of antioxidative effect of hormonal therapy in groups of women receiving different oestrogen doses.
Material and methods: The study group consists of 59 women receiving low dose HT containing 1 mg oestradiol + NETA. The control group includes 57 women with HT containing 2mg oestradiol + NETA. ROI generation was evaluated in 20 µl peripheral blood samples. Spontaneous ROI generation and generation after neutrophil activation with stimulators formyl-metionyl-leucylphenyloalanin (fMLP), phorbol acetate (PMA) and zymosan was measured. Luminol was used as an enhancer of chemiluminescence. Chemiluminescence associated with oxidation burst was measured with Luminometr 1251 at stable temperature during a 30 minute period (15 readings). Measurements were performed before applying continuous oestrogen-progestin hormonal replacement therapy, after 3 and 6 months of this therapy.
Results: Evaluating HT influence on ROI generation in the mentioned groups, we found no statistically significant differences.
Conclusion: Hormonal therapy antioxidative effect does not depend on oestrogen dose.