Antioksidanların normal ve diyabetik sıçan kemik ve dokularına etkilerinin moleküler düzeyde biyofiziksel olarak araştırılması


Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Biyolojik Bilimler Bölümü, Türkiye

Tezin Onay Tarihi: 2004

Tezin Dili: İngilizce

Öğrenci: Handan Boyar

Danışman: FERİDE SEVERCAN

Özet:

In the first part of this study, the effect of diabetes mellitus on the long bones (femur and tibia) of the streptozocin induced diabetic rats and the effect of selenium (Se) treatment on these bones are investigated at molecular level by Fourier transform infrared (FTIR) spectroscopy, light and electron microscopy. In the second part of this study, the effect of selenium and vitamin E deficiency or selenium toxicity on rat bones have been studied by FTIR spectroscopy. The results of the first part of the present study revealed that the changes observed in the mineral and matrix phases of diabetic bones, briefly, the increase in the mineral crystal size, the decrease in the acid phosphate and carbonate content, the increase in the ratio of pyridinoline [Pyr] cross-links to dihydroxylysinonorleucine [DHLNL] cross-links present in collagen I of the bone tissue as well as the increase in the lipid to protein ratio of the matrix are quite similar to those seen in osteoporotic patients and animal models and confirms the evidence of diabetic osteoporosis. Histologic studies carried out with light and electron microscopy supported these findings. FTIR spectroscopic analysis revealed that sodium selenite treatment had some restoring effects on the deviated properties of the microstructure of diabetic bones. The results of the second part of this study revealed that the deficiency of selenium led to increase in the crystal size of the bone minerals, decreases in acid phosphate and labile carbonate content and increase in the Pyr to DHLNL ratio as in the case of diabetic bones. These results can be indicative of the importance of selenium in glucose metabolism.The results of Se excess group are similar to those of Se deficient group except that toxic amount of selenium led to increase in the relative amount of acid phosphate. This can affect the pH of the mineral environment