Involvements of TRPV1 and TRPV4 channels in regulatory function to maintain bladder stability during urine storage: integrated analysis of behavior and reflex

利用瞬时受体电位香草样蛋白（TRPV）1敲除（KO）小鼠和TRPV4-KO小鼠，研究了TRPV1和TRPV4通道在调节下尿路活性中的功能作用。新型代谢笼对排尿行为的分析表明，TRPV4-KO小鼠的排尿频率明显高于TRPV1-KO小鼠，而TRPV1-KO小鼠表现出相似的VFD。在无麻醉条件下使用体内膀胱造影评估反射性排尿，结果显示TRPV1-KO和TRPV4-KO小鼠均表现出大量的非排尿性膀胱收缩（NVCs），而WT几乎没有出现NVCs。这些结果表明，TRPV1和TRPV4通道可能参与调节以稳定尿储存过程中的逼尿肌活动，并且有意识的TRPV4- ko小鼠比TRPV1- ko小鼠更容易发生短暂但反复困扰的NVCs，因此更容易导致尿失禁。

These studies using transient receptor potential vanilloid (TRPV)1-knock out (KO) mice and TRPV4-KO mice were conducted to examine functional roles of TRPV1 and TRPV4 channels in regulation of lower urinary tract activity. Analysis of voiding behavior with novel metabolic cages showed that TRPV4-KO mice have markedly higher voiding frequency and TRPV1-KO mice exhibit similar VFD.Evaluation of reflex micturition under decerebrate unanesthetized conditions using in vivo cystometrograms revealed that both TRPV1-KO and TRPV4-KO mice exhibit a large number of non-voiding bladder contractions (NVCs) whereas WT hardly show NVCs. These results suggested the possibilities that TRPV1 and TRPV4 channels are involved in modulation to stabilize detrusor activity during urine storage and that conscious TRPV4-KO mice are more vulnerable to NVCs, which are transient but repeatedly-bothering events, than TRPV1-KO mice, therefore leading to urinary incontinence more easily.