Fathollahi Ali, Daneshgari Firouz, Hanna-Mitchell Ann T
Urology Institute, Case Western Reserve University, Cleveland, OH., USA.
Curr Urol. 2015 Sep;8(3):113-8. doi: 10.1159/000365701. Epub 2015 Sep 4.
This article reviewed the results of studies done on animals that assessed effects of melatonin on bladder function. Melatonin does not change strip relaxation on its own. However, pre-treatment with melatonin decreases contractile responses induced by phenylephrine, acetylcholine, bethanechol and KCl in a dose-dependent manner. The contractile responses induced by the direct calcium channel openers are significantly decreased by melatonin pre-treatment. It also binds to Ca(2+)-activated calmodulin, and prevents it from activating myosin light-chain kinase. It may have direct effects on ion channels which are responsible for regulating bladder contraction. Its other mode of action on bladder occurs via the brain GABAA receptor. Melatonin is an antioxidant. In bladder, treatment with melatonin prevents elevations in malondialdehyde levels, reverses changes in glutathione levels, and decreases myeloperoxidase levels compared with oxidative injury. It can normalize age induced bladder dysfunction through its antioxidant effects, inhibiting smooth muscle contractility directly and restoring impaired contractility via normalization of Ca(2+) handling and sensitizations pathways. It attenuates the severity of cystitis and inflammation. Mast cell proliferation and activation are increased in cystitis, but decrease by melatonin treatment. Also, there is a decrease in expression levels of pro-inflammatory cytokines after melatonin treatment.
本文综述了对动物进行的研究结果，这些研究评估了褪黑素对膀胱功能的影响。褪黑素本身不会改变肌条舒张。然而，褪黑素预处理能以剂量依赖的方式降低去氧肾上腺素、乙酰胆碱、氨甲酰甲胆碱和氯化钾诱导的收缩反应。褪黑素预处理能显著降低直接钙通道开放剂诱导的收缩反应。它还与钙激活钙调蛋白结合，并阻止其激活肌球蛋白轻链激酶。它可能对负责调节膀胱收缩的离子通道有直接作用。它对膀胱的另一种作用方式是通过脑γ-氨基丁酸A受体。褪黑素是一种抗氧化剂。在膀胱中，与氧化损伤相比，褪黑素治疗可防止丙二醛水平升高，逆转谷胱甘肽水平变化，并降低髓过氧化物酶水平。它可以通过其抗氧化作用使年龄诱导的膀胱功能障碍正常化，直接抑制平滑肌收缩，并通过使钙处理和敏化途径正常化来恢复受损的收缩力。它减轻膀胱炎和炎症的严重程度。膀胱炎时肥大细胞增殖和活化增加，但褪黑素治疗可使其减少。此外，褪黑素治疗后促炎细胞因子的表达水平降低。
