title: ACTH-induced stress in weaned sows impairs LH receptor expression and steroidogenesis capacity in the ovary.
abstract: BACKGROUND
  Stress has been proved to impair the porcine reproduction soundly. Endocrine disruption, which is closely related to the persistent follicles, is possibly one of the results of stress, although the mechanism is unclear. Since the expression of luteinizing hormone receptor (LHR) in ovarian follicular wall and concentrations of steroid hormone in follicular fluid are related to the development of persistent follicles, this study is designed to evaluate the effect of administered adrenocorticotrophic hormone (ACTH) to weaned pigs on their ovarian steroidogenesis capacity and LHR expression.
  
  
  METHODS
  Ten multiparous sows were weaned and randomly divided into two groups (n = 5 each). Sows received 1 IU/kg ACTH (ACTH group) or saline (control group) every 8 h from days 3-9 after jugular vein intubation. Blood samples were collected throughout the experiment, and ovaries were collected after slaughter on day 10. Follicular fluid (FF) was used to determine the steroid hormone concentrations. The ovarian follicle wall was obtained and stored in liquid nitrogen to detect mRNA levels.
  
  
  RESULTS
  The plasma cortisol concentration was significantly (P < 0.01) elevated after ACTH injection. The estradiol (E2) and androstenedione (ASD) concentrations in FF were significantly lower (P < 0.05) in the ACTH group than in the control group. The LHR, 3β-hydroxysteroid dehydrogenase (3β-HSD), cytochrome P450 aromatase (P450arom), and cytochrome P450 17a-hydroxylase (P450c17) mRNA levels were significantly (P < 0.05) reduced in the ACTH group. The steroidogenic acute regulatory protein (StAR) level and cytochrome P450 side-chain cleavage (P450scc) was lower in the ACTH group than in the control group, but the difference was not statistically significant (P > 0.05). Immunostaining results revealed 3β-HSD,P450c17, and LHR expression in theca cells, and P450arom expression in granulosa cells. Immunohistochemical staining showed significant differences in the distribution of 3β-HSD, P450c17, LHR, and P450arom between the two groups.
  
  
  CONCLUSIONS
  These findings indicated that ACTH significantly diminished the LHR expression and steroidogenesis capacity of the ovaries of weaned sows.
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Weigang 1, Nanjing, 210095, China.
authors.forename: H S
authors.initials: HS
authors.lastname: Zhu
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Weigang 1, Nanjing, 210095, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Qian
authors.affiliation: College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.
authors.forename: H L
authors.initials: HL
authors.lastname: Liu
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Weigang 1, Nanjing, 210095, China. b_endong@njau.edu.cn.
authors.forename: E D
authors.initials: ED
authors.lastname: Bao
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000235:genetics / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000735:Androstenedione / Q000378:metabolism; D000818:Animals; D001141:Aromatase / Q000235:genetics / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D005260:Female; D015571:Follicular Fluid / Q000378:metabolism; D012739:Gonadal Steroid Hormones / Q000096:biosynthesis*; D006854:Hydrocortisone / Q000097:blood; D007150:Immunohistochemistry; D007986:Luteinizing Hormone / Q000378:metabolism; D010053:Ovary / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011974:Receptors, LH / Q000235:genetics / Q000378:metabolism*; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics / Q000378:metabolism; D013552:Swine; D014886:Weaning
chemical_list: D012739:Gonadal Steroid Hormones; D012333:RNA, Messenger; D011974:Receptors, LH; D000735:Androstenedione; D004958:Estradiol; D000324:Adrenocorticotropic Hormone; D007986:Luteinizing Hormone; D015096:3-Hydroxysteroid Dehydrogenases; D001141:Aromatase; D013254:Steroid 17-alpha-Hydroxylase; D006854:Hydrocortisone
keywords: ACTH; LH receptor; Steroidogenesis; Stress; Weanling sows