Expression and Distribution of the Sweet Taste Receptor Isoforms T1R2 and T1R3 in Human and Rat Bladders
Expression and Distribution of the Sweet Taste Receptor Isoforms T1R2 and T1R3 in Human and Rat Bladders
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DOI：
10.1016/j.juro.2011.07.083
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发表时间：
2011-12-01
影响因子：
6.6
通讯作者：
Tincello, Douglas G.
中科院分区：
文献类型：
--
作者：
Elliott, Ruth A.;Kapoor, Shalini;Tincello, Douglas G.
目的：人造甜味剂增强膀胱收缩。我们假设人工甜味剂会激活膀胱中的甜味受体。因此，我们研究了人和大鼠膀胱中甜味受体的表达。材料和方法：从石蜡块上切下人和大鼠膀胱的切片并通过免疫组织化学染色以检测T1R2/3甜味受体的表达。对膀胱匀浆进行十二烷基硫酸钠-聚丙烯酰胺电泳，然后进行免疫印迹检测 T1R2/3 受体表达。将具有和不具有尿路上皮的大鼠膀胱条悬浮在器官浴中。在糖精 (Sigma-Aldrich (R))（10(-8) 至 10(-3) M）不存在和存在的情况下测定对 10 Hz 电场刺激的收缩反应。还测定了在糖精不存在和存在以及糖精加锌的情况下对 KCl 的反应。 结果：T1R2/3 甜味受体在人和大鼠膀胱尿路上皮中表达。 3 种尿路上皮细胞（尤其是伞细胞）的质膜中存在明显的免疫染色。免疫印迹显示人类和大鼠膀胱匀浆中预期分子量的条带。仅当膀胱条中存在尿路上皮时，糖精才会因电场刺激而增强大鼠膀胱平滑肌收缩。锌阻断了糖精对KCl反应的增强作用。结论：T1R2/3甜味受体在人和大鼠膀胱尿路上皮中表达。人工甜味剂激活这些受体可能会导致膀胱收缩增强。
Purpose: Artificial sweeteners augment bladder contraction. We hypothesized that artificial sweeteners activate sweet taste receptors in the bladder. Thus, we investigated the expression of sweet taste receptors in human and rat bladders.Materials and Methods: Sections of human and rat bladders were cut from paraffin blocks and stained by immunohistochemistry for the expression of T1R2/3 sweet taste receptors. Bladder homogenates were subjected to sodium dodecyl sulfate-polyacrylamide electrophoresis, followed by immunoblotting for T1R2/3 receptor expression. Rat bladder strips with and without urothelium were suspended in organ baths. The contractile response to 10 Hz electrical field stimulation was determined in the absence and presence of saccharin (Sigma-Aldrich (R)) (10(-8) to 10(-3) M). Responses to KCl in the absence and presence of saccharin, and saccharin plus zinc were also determined.Results: T1R2/3 sweet taste receptors were expressed in human and rat bladder urothelium. Immunostaining was evident in the plasma membrane of the 3 urothelial cell types, particularly umbrella cells. Immunoblotting revealed bands at expected molecular weights in human and rat bladder homogenates. Saccharin augmented rat bladder smooth muscle contraction due to electrical field stimulation only when urothelium was present in the bladder strip. Zinc blocked the enhancing effect of saccharin on responses to KCl.Conclusions: T1R2/3 sweet taste receptors are expressed in human and rat bladder urothelium. Activation of these receptors by artificial sweeteners may result in augmented bladder contraction.