Department of Animal Science and Technology, Hebei Agricultural University, Baoding, China.
Ecotoxicol Environ Saf. 2021 Dec 20;227:112922. doi: 10.1016/j.ecoenv.2021.112922. Epub 2021 Oct 23.
As one of the most harmful gases in the livestock house, ammonia is recognized as an environmental stressor by Environmental Protection Agency (United States). The study aimed to explore the effect of ammonia on hypothalamic-pituitary-ovarian (HPO) axis of rabbits. A total of ninety two-month-old female IRA rabbits were randomly divided into three groups, and were kept in animal environment control rooms for four weeks at college of animal science and technology, Hebei Agricultural University (Baoding, China). The rabbits in the control group were kept under ammonia concentration of < 3 ppm. The two treatment groups were kept under ammonia concentration of 30 ppm and 50 ppm. Hypothalamus, pituitary, and ovary were collected for hematoxylin and eosin (HE) staining, immunohistochemistry, terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Serum was collected for enzyme-linked immunosorbent assay (ELISA).
Histopathological examination revealed that exposed to excess ammonia damaged the morphology and structure of hypothalamus, pituitary, and ovary. TUNEL assay revealed that apoptosis rate increased in hypothalamus, pituitary, and ovary. The protein expression levels of Bcl-2associated X protein (Bax) and Caspase-9 increased, while B-cell lymphoma-2 (Bcl-2) decreased, resulting in apoptosis. Moreover, the concentration of gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and progesterone (PROG) reduced in plasma. The mRNA expression of FSH and LH in pituitary and follicle-stimulating hormone receptor (FSHR), E2, PROG in ovary as well as decreased, indicated hormone secretion disorder.
The results indicated that ammonia exposure damaged hypothalamus, pituitary, and ovary, caused hormone secretion disorder and apoptosis.
氨气作为畜舍中最有害的气体之一，被美国环境保护署（EPA）认定为环境应激物。本研究旨在探讨氨气对家兔下丘脑-垂体-卵巢（HPO）轴的影响。将 92 月龄雌性 IRA 兔 92 只随机分为 3 组，在河北农业大学动物科技学院动物环境控制室饲养 4 周。对照组兔饲养在氨气浓度<3ppm 的环境中，两个处理组兔饲养在 30ppm 和 50ppm 的氨气浓度环境中。收集下丘脑、垂体和卵巢进行苏木精和伊红（HE）染色、免疫组织化学、末端脱氧核苷酸转移酶（TdT）dUTP 缺口末端标记（TUNEL）和定量逆转录-聚合酶链反应（qRT-PCR）。采集血清进行酶联免疫吸附试验（ELISA）。
组织病理学检查显示，暴露于过量氨气会损害下丘脑、垂体和卵巢的形态和结构。TUNEL 检测显示，下丘脑、垂体和卵巢的细胞凋亡率增加。B 细胞淋巴瘤-2 相关 X 蛋白（Bax）和 Caspase-9 的蛋白表达水平增加，而 B 细胞淋巴瘤-2（Bcl-2）减少，导致细胞凋亡。此外，血浆中促性腺激素释放激素（GnRH）、卵泡刺激素（FSH）、黄体生成素（LH）、雌二醇（E2）和孕酮（PROG）的浓度降低。垂体中 FSH 和 LH 的 mRNA 表达以及卵泡刺激素受体（FSHR）、E2、PROG 在卵巢中的表达降低，表明激素分泌紊乱。
结果表明，氨气暴露会损害下丘脑、垂体和卵巢，导致激素分泌紊乱和细胞凋亡。
