整合膜蛋白对药物在血-前列腺转运中的影响规律与调节利用

Prostatitis is an important male-specific disease, but due to the presence of blood-prostate barrier (BPB), the drug can not be effectively transported to the target tissue site, severely restricting the efficacy of such diseases. Currently, the accurate positioning of BPB in prostate, the material basis and mechanism of action are not elucidated. Is it located in the prostate gland microvascular endothelial or glandular epithelium? It is known that claudins (CLA) is an important molecule that connects cells closely to form a physiological barrier such as blood-brain, our previous studies have found that the above proteins are continuously expressed in both the vascular endothelial cells and the epithelial cells of prostate, which resulting in the concentration gradient of levofloxacin between cells. It is suggested that the distribution of CLA is related to BPB, which may be the key material basis of BPB formation. We have established a multi-site microdialysis probe implantation model of canine prostate. This project aims to use this model and cell experiments to study the distribution characteristics of CLA in prostatic tissues, using microdialysis and LC / MS-MS techniques in the sampling of multiple parts of the body to determine the pharmacokinetic characteristics of representative drugs in the prostate gland. To investigate the influence rules of diseases and other regulatory factors on BPB through CLA, and try to make clear the accurate positioning of BPB and explore its material basis, mechanism of action and regulatory tools, and provide experimental and theoretical basis for individual drug treatment of prostate diseases and the new formulation design.

前列腺炎是男性特有的重要疾病，但由于血-前列腺屏障（BPB）的存在常使药物无法有效转运至目标组织部位，严重制约该类疾病的疗效。目前，BPB在前列腺的准确定位、物质基础和作用机制均未阐明，其位于微血管内皮还是腺管上皮尚待证明。已知整合膜蛋白（CLA）是细胞间紧密连接构成血-脑等生理屏障的重要分子，我们前期研究已发现前列腺血管内皮细胞及腺管上皮细胞均连续表达上述蛋白，造成左氧氟沙星在其间存在浓度梯度。提示CLA分布与BPB相关，可能为构成BPB的关键物质基础；并已突破难关建立犬前列腺多部位微透析探针植入模型。本项目拟应用该模型及细胞实验考察CLA在前列腺的分布规律，采用微透析与LC/MS-MS技术在体多部位取样测定代表性药物在前列腺转运的局部药动学特点，研究疾病及其他调控因素通过CLA对BPB的影响规律，明确BPB的准确定位，探究其物质基础、作用机制和调控手段，为前列腺疾病个体化治疗提供依据。

前列腺炎是男性特有的重要疾病，但由于血-前列腺屏障（BPB）的存在常使药物无法有效转运至目标组织部位，严重制约该类疾病的疗效。目前，BPB在前列腺的准确定位、物质基础和作用机制均未阐明。已知整合膜蛋白（CLA）是细胞间紧密连接构成血-脑等生理屏障的重要分子，本项目在前期研究的基础上，以比格犬和大鼠为实验对象，分别以左氧氟沙星和头孢拉定为工具药物，采用微透析与HPLC技术在体多部位取样测定代表药物在前列腺转运的局部药动学特点，研究疾病及其他因素对BPB的影响规律。.分别以静脉注射的方式给予头孢拉定和左氧氟沙星两种药物后，以比格犬体内药物在前列腺组织中的分布程度与血液中分布程度之比（前列腺AUC0-t/血液AUC0-t）表示药物透过血-前列腺屏障，其值分别为69.32%、63.28%，两者相当，前列腺对两种药物分布的屏障作用无明显差异。以静脉注射方式给予两种不同发育程度的大鼠左氧氟沙星药物后，未成熟大鼠（5周龄）与成熟大鼠（10周龄）前列腺组织中与血液中药物分布程度的比值分别为90.62%和63.83%；成熟大鼠慢性前列腺炎模型中，药物在前列腺与血液分布程度的比值为85.26%。未成熟大鼠的前列腺屏障功能较低，提示未成熟大鼠前列腺屏障功能未完全建立；前列腺慢性细菌性感染后，前列腺药物屏障作用明显下降。免疫组织化学结果显示，上述未成年大鼠及前列腺慢性细菌性感染后大鼠的前列腺腺管上皮CLA-3表达及血管内皮细胞EBA的表达较正常成年大鼠的表达明显降低，提示CLA-3和EBA可能参与了血-前列腺屏障的产生机制，而同期考察的AQP-1,3,5、P-gp等蛋白表达缺乏明显相关性。.由于前列腺腺管非常细小且弯曲，微透析探针无法植入，故现有研究尚不能完全明确药物血前列腺屏障的准确定位，即无法确定其主要存在于前列腺血管内皮与前列腺间质之间，还是间质与前列腺腺管上皮之间，有待进一步研究。