Department of Experimental Biology, Faculty of Medicine, University of Porto, Porto, Portugal.
Eur Urol. 2012 Jun;61(6):1178-84. doi: 10.1016/j.eururo.2012.01.046. Epub 2012 Feb 1.
OnabotulinumtoxinA (Onabot/A) has been used to treat detrusor overactivity disorders. The treatment is based on several injections of toxin throughout the bladder wall. However, injection protocols are not well established among clinicians, varying in dose and dilution.
Study the distribution and neurochemistry of cleaved synaptosome-associated protein of 25 kDa (cSNAP-25) after Onabot/A administration in the guinea pig bladder. In addition, we analyzed which factor, dose or volume, contributes more to the diffusion of the toxin.
DESIGN, SETTING, AND PARTICIPANTS: Guinea pig bladders were treated with Onabot/A via intramural injection or an instillation.
Bladder cryostat sections were processed for single or dual immunohistochemistry staining with antibodies against cSNAP-25, vesicular acetylcholine transporter, tyrosine hydroxylase, and calcitonin gene-related peptide. Different administration methods and doses were analyzed. Statistical analysis was performed using the chi-square test for colocalization studies after multiple injections and the t test for the evaluation of affected fibers after a single injection.
cSNAP-25 immunoreactive fibers were abundant throughout the bladder tissue in the mucosa and muscular layer. Double labeling showed that parasympathetic fibers are more affected than sympathetic or sensory. A single Onabot/A injection is more effective if diluted in a higher volume. Onabot/A instillation in the bladder does not cleave SNAP-25 protein.
A single Onabot/A injection spreads the neurotoxin activity to the opposite side of the guinea pig bladder. This action is more evident when high saline volumes are used to dissolve Onabot/A. The toxin cleaves the SNAP-25 protein mainly in cholinergic but also in adrenergic and sensory fibers. In contrast with intramural injection, instillation of Onabot/A does not cleave SNAP-25 in nerve fibers.
肉毒毒素 A（Onabot/A）已被用于治疗逼尿肌过度活动症。该治疗方法基于在整个膀胱壁上进行多次毒素注射。然而，在临床医生中，注射方案并不完善，剂量和稀释度各不相同。
研究豚鼠膀胱内给予 Onabot/A 后裂解突触相关蛋白 25kDa（cSNAP-25）的分布和神经化学。此外，我们分析了哪个因素，剂量或容量，对毒素的扩散贡献更大。
设计、设置和参与者：通过壁内注射或灌注将豚鼠膀胱用 Onabot/A 处理。
膀胱冷冻切片用针对 cSNAP-25、囊泡乙酰胆碱转运体、酪氨酸羟化酶和降钙素基因相关肽的单或双重免疫组织化学染色进行处理。分析了不同的给药方法和剂量。使用多个注射后的卡方检验进行共定位研究，以及单次注射后受影响纤维的 t 检验进行统计分析。
cSNAP-25 免疫反应性纤维在黏膜和肌层的整个膀胱组织中都很丰富。双标记显示，副交感神经纤维比交感神经或感觉神经更受影响。如果在更高体积的盐水中稀释，单次 Onabot/A 注射更有效。膀胱内灌注 Onabot/A 不会裂解 SNAP-25 蛋白。
单次 Onabot/A 注射可将神经毒素活性扩散到豚鼠膀胱的对侧。当使用高生理盐水体积溶解 Onabot/A 时，这种作用更为明显。毒素主要裂解胆碱能纤维中的 SNAP-25 蛋白，但也裂解肾上腺素能和感觉纤维中的 SNAP-25 蛋白。与壁内注射相比，灌注 Onabot/A 不会裂解神经纤维中的 SNAP-25 蛋白。
