Tibolone and its metabolits: a pharmacology, tissue's specifics and effects on experimental models of tumoures

Tibolone represents steroid with wear estrogenic, progestagenic and androgenic properties, which can use as alternative usual hormonal replacement therapy (HRT). A series experiments for study influence of tibolone and its metabolits on a tissues in vitro and in vivo was conducted. The tissues selectivity of tibolone was found in a bone, where the estrogenic activity restores of a bones weight and quality the rats bone after ovarioectomy and the absence of estrogenic activity prevents of endometrial proliferation. Tibolone did note stimulate the cellular proliferation in the lines of tumoures crates and reduced a load of a tumour at the tumoures of mammary glands, called DMBA as on a model of preventive maintenance. It was shown that tibolone and each of from three metabolits considerably reduce in average load of the tumour after 10 weeks of treatment. These results show, that metabolits can introduce contribution to final effect of tibolone in the experiments in vivo and that metabolism plays a key role in a problem selective tissues effects of tibolone.