Benign prostatic hyperplasia (BPH) is common in aged dogs, but the pathogenesis has not been clearly elucidated. A total of 33 male Iranian dogs of mixed breed and in three age groups (under 3 years [n = 10]; 3–6 years [n = 15]; over 6 years [n = 8]), were investigated. BPH was confirmed by ultrasonography and histopathology in 13 cases. The highest prevalence of BPH was in the 3–6 years age group (8/15; 53.3%). Examination of sections of prostate that had been stained with Masson's trichrome revealed that the intensity of stromal smooth muscle cell staining (P <0.05) and the number of fibroblasts (P = 0.002) were significantly increased in BPH compared with normal prostate glands. Prostate cells from dogs with BPH (n = 13) had a significantly higher intensity of cytoplasmic immunolabelling with antibodies against glial cell line-derived neurotrophic factor (GDNF), cytokeratin (CK) AE1/AE3, vimentin, fibroblast growth factor-1 (FGF-1) and prostate-specific antigen (PSA), compared with normal prostate glands (n = 20) (P = 0.001), except for PSA, which was negative in both normal and BPH affected prostates. The overexpression of GDNF and FGF-1 in stromal and epithelial cells of prostate glands of dogs with BPH suggests that GDNF has a paracrine or autocrine role in stimulating cellular proliferation. GDNF overexpression may also play a pathogenetic role in promoting chronic prostatitis and increasing fibrosis and the smooth muscle component of the prostate gland in BPH.

良性前列腺增生（BPH）在老年犬中很常见，但其发病机制尚未明确阐明。共调查了 33 只伊朗雄性混合品种和三个年龄组的狗（3 岁以下 [n = 10]；3-6 岁 [n = 15]；6 岁以上 [n = 8]）。13例经超声和组织病理学证实为BPH。BPH 的最高患病率是 3-6 岁年龄组（8/15；53.3%）。经马松三色染色的前列腺切片检查显示基质平滑肌细胞染色强度（P  <0.05）和成纤维细胞数量（P = 0.002) 与正常前列腺相比，BPH 显着增加。来自患有 BPH 的狗 (n = 13) 的前列腺细胞具有显着更高的细胞质免疫标记强度，其中包含针对神经胶质细胞系衍生神经营养因子 (GDNF)、细胞角蛋白 (CK) AE1/AE3、波形蛋白、成纤维细胞生长因子-1 (FGF) 的抗体-1) 和前列腺特异性抗原 (PSA)，与正常前列腺 (n = 20) 相比 ( P = 0.001)，除了 PSA，它在正常和 BPH 影响的前列腺中均为阴性。GDNF 和 FGF-1 在患有 BPH 的狗的前列腺的基质和上皮细胞中的过度表达表明 GDNF 在刺激细胞增殖方面具有旁分泌或自分泌作用。GDNF 过度表达也可能在促进慢性前列腺炎和增加 BPH 中前列腺的纤维化和平滑肌成分方面发挥致病作用。