RESUMEN
OBJECTIVE: The purpose of this study was to investigate Vascular Endothelial Growth Factor Expression (VEGF) gene regulation by isoflavone in urinary tract tissues of castrated adult rats. DESIGN: Forty-five adult rats, 90 days old, weighting 200 g were used, receiving a soy-free ration. The animals were castrated for drug administration for 30 days (125 microg genisteine/g body weight/day) and sacrificed, divided into three groups: Group I-control; Group II-started isoflavone administration on the 5th day after castration; Group III-started isoflavone administration on the 28th day after castration. RNA was isolated from each bladder and urethra. Determination of VEGF gene regulated by isoflavone was obtained using a semiquantitative RT-PCR and immunohistochemistry of total RNA isolated from bladder and urethra. RESULTS: Our results demonstrate that isoflavone was able to upregulate mRNA level of the VEGF gene in the lower urinary tract of rats in Group II, where isoflavone administration was started at an early phase of estrogen deprivation, while in Group III, where isoflavone administration was started in the late phase of hypoestrogenism, did not show alteration of bladder and urethra VEGF gene expression, compared to placebo, maintaining the same level of the castrated rats without treatment. CONCLUSIONS: The data indicate that VEGF expression in rats is also regulated by isoflavone in early phase of hypoestrogenism.