Biomechanical evaluation of effects of estrogen, selective estrogen receptor modulator drugs and vitamin K2 on osteoporotic bone


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Mühendislik Bilimleri Bölümü, Türkiye

Tezin Onay Tarihi: 2004

Öğrenci: ARZU GÜL TAŞCI

Danışman: DİLEK KESKİN

Özet:

In this study different bioactive agents were used to investigate their single and combined effects on biomechanical properties of osteoporotic bone. Estrogen, the most common hormon replacement therapy (HRT) agent, was used in single and combined with raloxifen, a well known osteoporosis drug. Despite their high clinical uses, they have not been tried before, in combination. They act as agonist of each other in bone and antagonist of each other in uterus and mammary glands. Hence it was expected to prevent HRT side effects by using combinations while enhancing the healing on osteoporotic bone. So, the study was designed to see the interaction effects of these two agents on bone and uterus, to observe the mechanical behaviour upto fracture, and to investigate the bone mechanical properties by strain gauges and bending theory with ovariectomized rat model. Second approach to osteoporosis treatment, VitK2 was chosen to be used alone or in combination with raloxifen in same model. Although recent studies mentioned the effects of VitK2 on bone, its rebuilding or repair effect was not completely established. So, VitK2-bone relation was aimed to be clarified with the project.VitK2 raloxifen combination was also a new study, that has not been carried out so far. As a result of mechanical tests, it was found that E+R combination is the most effective treatment. All treatment̕s were resulted in numerically (though not statistically significant) higher values on femur mechanical properties, and significantly better on tibia compared to the untreated controls. VitK2 performs well in energy absorption upto fracture, but worse in others (PL, YL etc.) compared to other treatments indicating that it plays a specific role in modifying bone structure thus, rendering bone stronger under high stress. However, similar to estrogen case, its combination with raloxifen performs better than