The Effect of Estrogen on Expression of Neuronal and Endothelial Nitric Oxide Synthase and on Histologic Composition in Rat Bladder and Urethra / 대한비뇨기과학회지

ABSTRACT

PURPOSE: We investigated the effects of estrogen on the expression of neuronal nitric oxide synthase(nNOS) and on endothelial nitric oxide synthase(eNOS), and furthermore elucidated its effect on the histologic composition of the rat bladder and urethra. MATERIALS AND METHODS: Forty-five mature female Sprague-Dawley rats (10-11 weeks, 235-250g) were randomly assigned to one of three groups control group(C), oophorectomy group(O), or hormone(estradiol) replacement group(H). The degree of expression of nNOS and eNOS in bladder and urethral tissues was investigated using immunohistochemical staining, and tissue was described as mucosa, smooth muscle, or vessel. We also investigated changes in histologic composition using Masson's trichrome stain. RESULTS: In bladder and urethra, the expression rates of nNOS and eNOS significantly increased in the O group, but decreased in the H group (p< 0.05), except for nNOS in the mucosa and smooth muscle of the bladder. The relative collagen ratios significantly increased in bladder and urethra in the O group, to 121.2+/-12.7% and 135.5+/-25.2%, respectively, but decreased to 95.6+/-15.2% and 93.7+/-12.8% in the H group, respectively (p<0.05). CONCLUSIONS: These data suggest that estrogen replacement therapy decreases nNOS and eNOS expression and the collagen component in the urethra.