Ness Timothy J, DeWitte Cary
Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL 35205, USA.
Department of Anesthesiology and Perioperative Medicine, University of Alabama at Birmingham, Birmingham, AL 35205, USA.
Neurosci Lett. 2025 Jan 18;846:138090. doi: 10.1016/j.neulet.2024.138090. Epub 2024 Dec 17.
Rats which experienced neonatal bladder inflammation (NBI) have been demonstrated to exhibit latent bladder hypersensitivity with a nociceptive component that becomes unmasked by a second inflammatory insult as an adult. Manifested as augmented reflex and neuronal responses to urinary bladder distension (UBD), these NBI-induced changes are revealed by using inflammation of nearby structures as an adult pretreatment. The effect of inflammation in distant structures is not known. These studies examined visceromotor reflex responses and lumbosacral spinal dorsal horn neuronal responses to UBD in rats and compared effects of segmental (hindpaw) versus hetero-segmental (forepaw or face) inflammatory pretreatments in 192 female Sprague-Dawley rats raised from birth. On postnatal days 14-16 these rats underwent either NBI or control procedures. As adults, these rats received control injections or 0.1 ml Complete Freund's Adjuvant (CFA) injections into one of four sites. Three days later they were studied in reflex or spinal single-cell neuronal experiments where responses were evoked by UBD. Visceromotor responses to UBD were more robust in rats which had injections in the hindpaw (either side) but were not significantly affected by forepaw or facial injections. Similar results were identified in L6/S1 neurons with more robust UBD-evoked responses observed in rats receiving hindpaw CFA injections but not forepaw injections. These results indicate that latent bladder hypersensitivity induced by NBI is made manifest by segmental, but not hetero-segmental inflammatory stimuli. This observation correlates with pain in patients with interstitial cystitis who often have flares in symptoms associated with inflammation of nearby structures.
已证实经历过新生期膀胱炎症（NBI）的大鼠表现出潜在的膀胱超敏反应，其伤害性成分在成年后会因第二次炎症刺激而显现出来。这些由NBI诱导的变化表现为对膀胱扩张（UBD）的反射和神经元反应增强，通过在成年后对附近结构进行炎症预处理来揭示。远处结构炎症的影响尚不清楚。这些研究检测了大鼠对UBD的内脏运动反射反应和腰骶部脊髓背角神经元反应，并比较了节段性（后爪）与异节段性（前爪或面部）炎症预处理对192只从出生起饲养的雌性Sprague-Dawley大鼠的影响。在出生后第14 - 16天，这些大鼠接受了NBI或对照程序。成年后，这些大鼠在四个部位之一接受对照注射或0.1毫升完全弗氏佐剂（CFA）注射。三天后，在反射或脊髓单细胞神经元实验中对它们进行研究，其中通过UBD诱发反应。对UBD的内脏运动反应在在后爪（任一侧）注射的大鼠中更强，但前爪或面部注射对其影响不显著。在L6/S1神经元中也发现了类似结果，在接受后爪CFA注射而非前爪注射的大鼠中观察到更强的UBD诱发反应。这些结果表明，由NBI诱导的潜在膀胱超敏反应通过节段性而非异节段性炎症刺激表现出来。这一观察结果与间质性膀胱炎患者的疼痛相关，这些患者的症状发作通常与附近结构的炎症有关。
