Effect of tibolone on cytochrome c oxidase I, beta-2-microglobulin and vascular endothelial growth factor gene expression in the lower urinary tract of castrated rats.

INTRODUCTION: The objective of this study was to evaluate the effect of tibolone on cytochrome oxidase I (COX I), beta-2-microglobulin (B2M) and vascular endothelial growth factor (VEGF) gene expression in the lower urinary tract of castrated rats. These genes are related to cell energy, cellular immunity and vascularization processes. METHODS: Fifty adult castrated rats remained at rest for 28 days. Thereafter they were randomly divided into two groups of 25 animals each. The lower urinary tract (bladder and urethra) was extracted in animals of one group and the other group received tibolone at a dose of 0.25 microg/animal/day for another 28 days followed by removal of the lower urinary tract. Total RNA was extracted from animals of both groups, forming two pools. After RT-PCR (reverse transcriptase polymerase chain reaction), expression of COX I, B2M and VEGF genes was evaluated by agarose gel electrophoresis, visualized by UV illumination. RESULTS: Expression of the three genes (COX I, B2M and VEGF) was greater in the group treated with tibolone. CONCLUSION: The use of tibolone increases the expression of COX, B2M and VEGF genes in the lower urinary tract as compared with that in castrated rats.