Department of Human Physiology, University of Warmia and Mazury in Olsztyn, Poland.
J Physiol Pharmacol. 2009 Oct;60 Suppl 4:77-81.
Pig has been used recently as an animal model for studying diseases of human urinary tract, however, the sensory innervations of urinary bladder in this species has not been yet described.
The present study was aimed at neurochemical characterization of sensory neurons of dorsal root ganglia (DRGs) supplying porcine urinary bladder.
Retrograde tracer Fast Blue (FB) was injected into the right half of the urinary bladder wall of six juvenile female pigs. Three weeks later ipsi- and contralateral DRGs of interest were harvested from all animals and a neurochemical characterization of retrogradely-labeled neurons was performed using routine single-immunofluorescence labeling technique on 10 microm-thick cryostat sections.
85% of spinal sensory neurons supplying porcine urinary bladder was located in ipsilateral sacral S3-S4 ganglia and in first coccygeal ganglion (Cq1),whereas rest of FB-positive (FB+) nerve cells were found in lumbar L3-L6 DRGs. FB+ neurons belonged mostly to the medium-sized (54%) and small-sized afferent perikarya (45%). Bladder sensory neurons contained substance P (SP), calcitonin gene-related peptide (CGRP), pituitary adenylate cyclase-activating peptide (PACAP), galanin (GAL), neuronal nitric oxide synthase (nNOS), somatostatin (SOM) and/or calbindin-28k (CB), and these neurons constituted 45%, 36%, 26%, 6%, 6%, 4% and 3% of all retrogradely traced DRGs perikarya, respectively. Distinct differences in the number of traced cells and their neuropeptide content were observed between the lumbar and sacral/coccygeal division of bladder-projecting DRG neurons. Thus, FB+ neurons expressing CGRP, GAL, nNOS or SOM were more numerous in lumbar DRGs (44%, 9%, 9% and 6%, respectively), than in sacral/coccygeal ganglia (23%, 2%, 1.5% and 0.3%, respectively). On the other hand, more FB+ cells expressed PACAP in sacral (31%) than in lumbar DRGs (23%). However, fractions of SP-IR or CB-IR bladder sensory neurons were similar in lumbar and sacral/coccygeal DRGs.
This novel description of both spatial and neurochemical organization pattern of porcine urinary bladder sensory innervation constitutes a basis for further functional studies aimed at unraveling neurogenic mechanisms of urinary bladder diseases.
猪最近被用作研究人类泌尿道疾病的动物模型，然而，这种物种的膀胱感觉神经支配尚未被描述。
本研究旨在对供应猪膀胱的背根神经节（DRG）感觉神经元进行神经化学特征描述。
将逆行示踪剂 Fast Blue（FB）注入 6 只幼年雌性猪的右侧膀胱壁。3 周后，从所有动物中取出感兴趣的同侧和对侧 DRG，并使用常规的单免疫荧光标记技术对 10 微米厚的冷冻切片进行逆行标记神经元的神经化学特征描述。
供应猪膀胱的 85%脊髓感觉神经元位于同侧骶骨 S3-S4 神经节和第一尾骨神经节（Cq1），而其余的 FB+神经细胞位于腰椎 L3-L6 DRG 中。FB+神经元主要属于中型（54%）和小型传入体（45%）。膀胱感觉神经元含有 P 物质（SP）、降钙素基因相关肽（CGRP）、垂体腺苷酸环化酶激活肽（PACAP）、甘丙肽（GAL）、神经元型一氧化氮合酶（nNOS）、生长抑素（SOM）和/或钙结合蛋白-28k（CB），这些神经元分别构成所有逆行追踪的 DRG 传入体的 45%、36%、26%、6%、6%、4%和 3%。在腰椎和骶骨/尾骨支配膀胱的 DRG 神经元之间，被追踪的细胞数量及其神经肽含量存在明显差异。因此，表达 CGRP、GAL、nNOS 或 SOM 的 FB+神经元在腰椎 DRG 中更为常见（分别为 44%、9%、9%和 6%），而在骶骨/尾骨神经节中则较少（分别为 23%、2%、1.5%和 0.3%）。另一方面，更多的 FB+细胞在骶骨（31%）中表达 PACAP，而在腰椎 DRG 中（23%）则较少。然而，SP-IR 或 CB-IR 膀胱感觉神经元在腰椎和骶骨/尾骨 DRG 中的比例相似。
本研究对猪膀胱感觉传入的空间和神经化学组织模式进行了新的描述，为进一步研究膀胱疾病的神经发生机制奠定了基础。
