Department of Anatomy and Histology, Faculty of Veterinary Medicine and Animal Sciences, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur-1706, Bangladesh; and Department of Veterinary Anatomy, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan; and Corresponding author. Email:
Laboratory of Veterinary Anatomy, Department of Veterinary Medicine, Okayama University of Science, Imabari, Ehime 794-8555, Japan; and Department of Veterinary Anatomy, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
Reprod Fertil Dev. 2021 Mar;33(5):319-327. doi: 10.1071/RD20150.
Although di-n-butyl phthalate (DBP) induces germ cell apoptosis, the underlying mechanism is not yet clear in quail. In this study, prepubertal quails were given a single dose of 500mg kg-1 DBP by gavage and were then killed 3, 6 and 24h after treatment. There was a significant reduction in intratesticular testosterone (ITT) concentrations and testicular steroidogenic enzyme mRNA expression and a significant increase in germ cell apoptosis in DBP-treated compared with control quails at all time points. Maximum apoptosis was detected 6h after treatment and the maximum reduction in testosterone concentrations was at 3h. To investigate whether DBP suppressed testicular steroidogenesis by affecting the hypothalamic-pituitary-testicular axis, we analysed pituitary LH subunit β (Lhb) mRNA expression and serum LH concentrations. At all time points, pituitary Lhb expression and serum LH concentrations were significantly decreased following DBP treatment. The present observations suggest the possibility that DBP blocked LH secretion from the hypothalamus and/or pituitary, thereby decreasing LH stimulation of Leydig cells and reducing ITT concentrations. DBP-induced decreases in ITT concentrations may cause changes to the physical structure of Sertoli cells, which, in turn, may induce germ cell apoptosis.
尽管邻苯二甲酸二正丁酯 (DBP) 可诱导生殖细胞凋亡，但在鹌鹑中其潜在机制尚不清楚。在这项研究中，未成年鹌鹑经灌胃给予 500mg/kg 的 DBP 单次剂量，然后在处理后 3、6 和 24 小时处死。与对照组鹌鹑相比，DBP 处理组鹌鹑的睾丸内睾酮 (ITT) 浓度、睾丸甾体生成酶 mRNA 表达显著降低，生殖细胞凋亡显著增加。在处理后 6 小时检测到最大凋亡，在 3 小时检测到最大的睾酮浓度降低。为了研究 DBP 是否通过影响下丘脑-垂体-睾丸轴抑制睾丸甾体生成，我们分析了垂体 LH 亚基 β (Lhb) mRNA 表达和血清 LH 浓度。在所有时间点，DBP 处理后垂体 Lhb 表达和血清 LH 浓度均显著降低。目前的观察结果表明，DBP 可能阻断了下丘脑和/或垂体的 LH 分泌，从而减少了 LH 对间质细胞的刺激，降低了 ITT 浓度。DBP 引起的 ITT 浓度降低可能导致支持细胞的物理结构发生变化，进而可能诱导生殖细胞凋亡。
