Estrogen replacement avoids the decrease of bladder innervations in ovariectomized adult virgin rats: in vivo stereological study.

INTRODUCTION AND HYPOTHESIS: The authors quantified the nerve fibers in the bladder wall of ovariectomized rats with and without estradiol replacement.
METHODS: This study was conducted on 40 Wistar rats (3 months old). Group 1: remained intact; Group 2: underwent bilateral ovariectomy, and after 30 days was started on subcutaneous sesame oil replacement (0.2 ml per day) for 90 days; Group 3: sham-operated, and after 30 days was started on subcutaneous sesame oil replacement (0.2 ml per day) for 90 days; Group 4: bilateral ovariectomy, and after 30 days was started on subcutaneous injection of 17β-estradiol (10 μg/kg body weight) for 90 days. S-100 was used to stain nerves myelinized fibers on paraffin rat bladder sections. The G-50 grid system was used to quantitatively analyze the fibers.
CONCLUSION: Long-term estrogen deprivation caused significant changes in bladder innervations, which can be characterized by a decreased number of nerve fibers by 65% (p < 0.001).