Chronic stress affects the reproductive health of mammals; however, the impact of adrenocorticotropin hormone (ACTH) level elevation during chronic stress on the reproduction of weaned sows remains unclear. In this study, nine weaned sows with the same parturition date were randomly divided into control group (n = 4) and ACTH group (n = 5). Each group received intravenous administration of ACTH three times daily for 7 days. Blood samples were collected every 3 h after injection. A radioimmunoassay was used to measure the concentrations of cortisol, luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone (P₄) and estradiol-17β (E₂) in the blood. Estrus was determined according to changes in the vulva and the boar contact test. The mRNA expressions of glucocorticoid receptor, FSH receptor, LH receptor (LHR) in the corpus luteum (CL) were detected by qRT-PCR. The results showed that ACTH administration substantially delayed the initiation of estrus and the pre-ovulatory LH peak. The sows of control group ovulated within 10 days and the ovulation rate was 100%, while it was 60% in the ACTH group. Two sows of ACTH group showed pseudo-estrus. The E₂ concentrations significantly decreased in the ACTH group at 36 h, 42 h and 66 h of the experimental period. The P₄ concentrations in the ACTH group significantly decreased at 132, 138, and 147 h of the experimental period. ACTH significantly reduced the LHR mRNA expression in CLs. In conclusion, long-term repeated ACTH administration affects the endocrinology, estrus onset, and ovarian function of weaned sows.

慢性压力会影响哺乳动物的生殖健康；然而，慢性应激期间促肾上腺皮质激素（ACTH）水平升高对断奶母猪繁殖的影响仍不清楚。本研究将9头分娩日期相同的断奶母猪随机分为对照组（n =4）和ACTH组（n =5）。每组每天3次静脉注射ACTH，共7天。注射后每 3 小时采集一次血样。放射免疫测定法用于测量皮质醇、黄体生成素 (LH)、卵泡刺激素 (FSH)、孕酮 (P ₄ ) 和雌二醇-17β (E _{2 ) 的浓度}) 在血液中。根据外阴变化和公猪接触试验确定发情。qRT-PCR检测黄体(CL)中糖皮质激素受体、FSH受体、LH受体(LHR)的mRNA表达。结果表明，ACTH 给药显着延迟了发情的开始和排卵前的 LH 峰值。对照组母猪10天内排卵，排卵率为100%，促肾上腺皮质激素组为60%。ACTH组2只母猪出现假发情。在实验期的36 h、42 h和66 h，ACTH组的E ₂浓度显着降低。ACTH组的P ₄浓度在实验期的132、138和147 h显着降低。ACTH 显着降低LHRCL中的mRNA表达。总之，长期反复使用ACTH会影响断奶母猪的内分泌、发情和卵巢功能。