水通道蛋白在大鼠前列腺的表达及意义

Expression and potential role of Aquaporin water channels in prostate of rats

目的探讨水通道蛋白(Aquaporins,AQPs)在大鼠前列腺的表达及意义。方法将雄性健康8周龄SD大鼠30只随机分为A组(对照组)、B组(去势组)和C组(去势+睾酮替代组)。每组10只分别测定血睾酮水平,脉冲式电流刺激盆神经收集前列腺液,测量前列腺液重量,计算前列腺湿重与体重比,免疫组化检测AQP1、AQP3和AQP4的表达及细胞定位,免疫印迹检测AQP1、AQP3和AQP4蛋白的表达。结果 B组大鼠血睾酮水平[(13.07±1.83)nmol/L]较A组[(92.37±16.23)nmol/L]显著减低(P<0.05),B组前列腺液分泌[(1.14±0.14)mg]较A组[(13.57±2.72)mg]显著减少(P<0.05),B组前列腺湿重与体重比(0.27±0.12)较A组(1.91±0.07)显著降低(P<0.05)。免疫组化结果显示,AQP1主要在大鼠前列腺间质的小动脉、小静脉壁表达,AQP3主要在前列腺腺泡上皮细胞膜表达,AQP4则更多的在腺泡上皮靠近基底膜处表达。免疫印迹结果显示,B组AQP1和AQP3的表达较A组均显著降低(P<0.05),各组中AQP4的表达无明显变化。结论 AQP1可能与前列腺的生长发育过程有关,AQP3和AQP4可能与前列腺分泌功能有关,雄激素降低后前列腺液分泌减少与AQP3的表达降低有关。

Objective To investigate the expression and potential role of Aquaporins（AQPs）in prostate of rats.Methods Healthy 8-week old Sprague-Dawley rats（n=30）were randomly divided into three group：group A（control group）,group B（castrated group）,group C（castrated and testosterone replacement group）.The serum level of testosterone was measured.The prostate fluid was collected by pulse electrical stimulation of the pelvic nerve.The ratio between prostate wet weight and body weight was calculated.The cellular localizations of AQP1,AQP3 and AQP4were detected by immunohistochemistry staining.The expressions of AQP1,AQP3 and AQP4were determined by Western Blotting.Results The serum level of testosterone was decreased significantly in group B than that of group A.The volume of prostate fluid in group B was significantly less that of than group A.The weight of prostate was significantly lighter after castrated.Immunohistochemistry staining showed the AQP1 was mainly expressed in the small artories and venules of prostate interstitium.AQP3 was mainly expressed throughout the acinar epithelia cell membrane.AQP4 was especially localized in the epithelium layer close to the basoleteral membrane.The protein expression of AQP1 and AQP3were significantly decreased in group B.There were no differences in the expression of AQP4 among all three groups.Conclusion AQP1 may associated with the growth of prostate.AQP3 and AQP4may play an important role in prostate secretion.Decreased prostate secretion after androgen deprivation may be partly due to the lower expression of AQP3.