title: Effects of resistin on porcine ovarian follicle steroidogenesis in prepubertal animals: an in vitro study.
abstract: BACKGROUND
  Resistin was first reported to be an adipocyte-specific hormone, but recent studies have indicated a connection between resistin and reproductive function. However, it is not yet known if resistin is expressed by the ovary and if it can affect steroidogenesis in ovarian follicles from prepubertal pigs.
  
  
  METHODS
  In this study, using real time PCR, immunoblotting, and ELISA, we quantified resistin expression and concentration in maturing ovarian follicles (small, 3-4 mm; medium, 4-5 mm; large, 6-7 mm) collected from prepubertal pigs. In addition, the dose-responsive effects of recombinant human resistin (0.1, 1, 10, and 100 ng/ml) on steroid hormone (i.e., progesterone [P4], androstendione [A4], testosterone [T], and estradiol [E2]) secretion in culture medium and steroidogenic enzyme (i.e., CYP11A1, 3betaHSD, CYP17A1, 17betaHSD, and CYP19A1) expression in ovarian follicles were determined.
  
  
  RESULTS
  We observed that resistin gene and protein expression increased significantly (P < 0.05) during follicular growth, with large follicles expressing the highest level of this adipokine. Recombinant resistin also increased P4, A4, and T secretion by up-regulating the steady state levels of CYP11A1, 3betaHSD, CYP17A1, and 17betaHSD. Recombinant resistin had no effects on E2 secretion and CYP19A1 expression in ovarian follicles.
  
  
  CONCLUSIONS
  Our results show resistin expression in ovarian follicles from prepubertal pigs for the first time. We also show that recombinant resistin stimulates steroidogenesis in ovarian follicles by increasing the expression of CYP11A1, 3betaHSD, CYP17A1, and 17betaHSD. The presence of resistin in the porcine ovary and its direct effects on steroidogenesis suggest that resistin is a new regulator of ovary function in prepubertal animals.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Rak-Mardyła
authors.forename: Martyna
authors.initials: M
authors.lastname: Durak
authors.forename: Ewa
authors.initials: E
authors.lastname: Lucja Gregoraszczuk
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000378:metabolism; D000735:Androstenedione / Q000378:metabolism; D000818:Animals; D001141:Aromatase / Q000378:metabolism; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D004958:Estradiol / Q000378:metabolism; D005260:Female; D006801:Humans; D015151:Immunoblotting; D006080:Ovarian Follicle / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D011994:Recombinant Proteins / Q000494:pharmacology*; D052243:Resistin / Q000378:metabolism / Q000494:pharmacology*; D012741:Sexual Maturation; D013254:Steroid 17-alpha-Hydroxylase / Q000378:metabolism; D013552:Swine / Q000254:growth & development / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D052243:Resistin; D013739:Testosterone; D000735:Androstenedione; D011374:Progesterone; D004958:Estradiol; D015067:17-Hydroxysteroid Dehydrogenases; D001141:Aromatase; D013254:Steroid 17-alpha-Hydroxylase; D002786:Cholesterol Side-Chain Cleavage Enzyme