The local immunity of the lower urinary tract (LUT) is often presumed to influence the development of ascending infections and local inflammation. Due to small ruminants being at a higher risk of developing obstructive urolithiasis after early castration, a relationship is expected to exist between disturbed local immunity, castration and disease. However, the underlying pathophysiology and histological correlation of this assumption are unknown. This study examines the local cellular immunity of the LUT in male lambs with respect to castration status or a recent history of obstructive urolithiasis. Various tissue samples were taken and examined. The sample consisted of 34 male lambs, aged six months (n = 11 early and n = 11 late castration; n = 12 intact) and eight rams that had undergone necropsy due to fatal outcome after obstructive urolithiasis. Immunohistochemical stainings for CD3-T-cells, CD79α-B-cells and MAC 387-macrophages were performed and compared among the groups. Whereas no global group differences were evident, significant differences were found for the localizations (P = 0.002) with a significant interaction between group and localization (P = 0.004). The immunohistochemical results suggest that castration did not affect the cell number, but did have an effect on the distribution pattern of local T-cells within the urethra. In the urolithiasis cases, a reduction of CD3-positive cells along the middle part of the urethra was noticeable.

下尿路 (LUT) 的局部免疫通常被认为会影响上行感染和局部炎症的发展。由于小型反刍动物在早期阉割后发生梗阻性尿石症的风险较高，因此预计局部免疫紊乱、阉割和疾病之间存在关系。然而，这一假设的潜在病理生理学和组织学相关性尚不清楚。本研究检查了雄性羔羊 LUT 在阉割状态或近期梗阻性尿路结石病史方面的局部细胞免疫。采集并检查了各种组织样本。样本包括 34 只 6 个月大的雄性羔羊（n  = 11 早期 阉割，n = 11 晚期阉割；n = 12 只完好无损）和 8 只因梗阻性尿石症后致命结果而进行尸检的公羊。对 CD3-T 细胞、CD79α-B 细胞和 MAC 387-巨噬细胞进行免疫组织化学染色并在各组之间进行比较。尽管没有明显的整体群体差异，但是发现了局部差异（P  = 0.002），并且群体与局部之间存在显着相互作用（P  = 0.004）。免疫组织化学结果表明去势不影响细胞数量，但确实对尿道内局部 T 细胞的分布模式有影响。在尿道结石病例中，沿尿道中部的 CD3 阳性细胞明显减少。