Onal Bulent, Levin Robert M, Kogan Barry A, Whitbeck Catherine, Chichester Paul, Walebowa Oteng, Mannikarottu Anita S
Albany College of Pharmacy, 106 New Scotland Avenue, Albany, NY 12208, USA.
BJU Int. 2007 Mar;99(3):674-9. doi: 10.1111/j.1464-410X.2006.06638.x.
To evaluate the effect of maturation and ageing on oestrogen-induced functional hypertrophy of the female rabbit bladder.
Twenty female rabbits were separated into two groups of 10 each by age, young (immature) and old rabbits and each age group was subdivided into three subgroups. The rabbits in subgroup 1 were controls, subgroup 2 were ovariectomized (Ovx) and subgroup 3 were Ovx and received 17-beta oestradiol (1 mg/kg/day) by a subcutaneous slow-release tablet implant. After 15 days of treatment, the rabbits were killed, the bladder was excised, and the body and base separated; two full-thickness longitudinal strips from the ventral surface of the bladder body, and one full-thickness strip from the base, were prepared for contractile studies. The contractile responses to electrical-field stimulation, carbachol, ATP and KCl were determined for both the bladder body and base strips. In addition, full-thickness strips of bladder body and base were fixed in formalin for histological and immunohistological studies.
Ovx plus oestradiol resulted in significant increases in bladder weight and responses to all forms of stimulation in young and old rabbits (except for the response to KCl). Vascular density and the smooth muscle (SM)/collagen ratio significantly increased after oestradiol replacement. Interestingly, the increase in vascular density was greater in the young than in the old rabbits.
The present study shows that oestrogen supplementation mediates a functional hypertrophy characterized by increased contractile responses to all forms of stimulation in both young and old rabbits. The increased contractile responses might be explained by the increases in vascular density and SM/collagen ratio.
评估成熟和衰老对雌激素诱导的雌性兔膀胱功能性肥大的影响。
20只雌性兔按年龄分为两组，每组10只，即年轻（未成熟）兔和老年兔，每个年龄组再细分为三个亚组。亚组1的兔为对照组，亚组2的兔行卵巢切除术（Ovx），亚组3的兔行Ovx并通过皮下缓释片剂植入接受17-β雌二醇（1mg/kg/天）。治疗15天后，处死兔，切除膀胱，将膀胱体和膀胱底分离；从膀胱体腹面制备两条全层纵向条带，从膀胱底制备一条全层条带，用于收缩研究。测定膀胱体和膀胱底条带对电场刺激、卡巴胆碱、ATP和氯化钾的收缩反应。此外，将膀胱体和膀胱底的全层条带固定在福尔马林中用于组织学和免疫组织学研究。
Ovx加雌二醇导致年轻和老年兔的膀胱重量显著增加，对所有形式刺激的反应增强（氯化钾刺激反应除外）。雌激素替代后血管密度和平滑肌（SM）/胶原蛋白比率显著增加。有趣的是，年轻兔的血管密度增加幅度大于老年兔。
本研究表明，补充雌激素介导了一种功能性肥大，其特征是年轻和老年兔对所有形式刺激的收缩反应增强。收缩反应增强可能是由于血管密度和SM/胶原蛋白比率增加所致。
