9600 Medical Center Dr.
Rockville, MD 20850
301 251 2801
800 208 3149

Reproductive Endocrinology and Toxicology Bioassays

Endocrine Disruptor Assays

John C. Landon, Ph.D., 301 251 2801 ext 253

Assays may be done under FDA/EPA GLP guidelines.

      1.  Hershberger bioassay (rat)

      2.  Pubertal development and thyroid function in female rats

      3.  Pubertal development and thyroid function in male rats

      4.  Uterotrophic bioassay (rat)

      5.  Estrogen receptor (ER) binding using recombinant human ER-alpha and beta

            or uterine cytosols

      6.  Androgen receptor (AR) binding using recombinant rat AR or rat ventral prostate cytosols

      7.  Transactivation assays in T47Dco or T47D-KBlue cells mediated by ER

      8.  Transactivation assays in CV-1 cells mediated by AR

      9.  Aromatase assays using recombinant human microsomal preparations


Assays may be done under FDA/EPA GLP guidelines.

All studies are custom-designed in collaboration with the client. Test compounds can be administered to animals by various routes including: oral, subcutaneous, intramuscular, intraperitoneal, intravenous, or topical.

Anti-Fertility Assays

  1. Broad screen: mating trials in female rats
  2. Mode of action studies:
    Anti-ovulatory in 4-day cyclic rat
    Postcoital assays to detect antifertility actions after ovulation in rat or rabbit
    Evaluation of hypothalamic-pituitary-gonadal axis
  3. Duration of action:
    Estrous cycle suppression in adult rat
    Menstrual cycle suppression in adult monkey
  1. Broad screen: mating trials in male rats
  2. Mode of action studies in rat, rabbit, or monkey:
    Evaluation of hypothalamic-pituitary-gonadal axis
    Semen analysis for sperm concentration, motility and morphology in rabbit or monkey; spermatid
    head counts in rats
    Histological evaluation of testis including tubule differentiation indices
    Leydig cell function - evaluation of testicular testosterone
    Sertoli cell function - seminiferous tubule fluid secretion (rat), serum inhibin B levels (rat or monkey),
Anti-gonadotropic Assays
  1. LH/FSH suppression in the castrated adult male rat model
  2. Testosterone suppression in the adult intact male monkey model
Spermicidal Activity
  1. Vaginal contraceptive efficacy in the adult female rabbit: mating trial with proven fertile bucks after administration of vaginal preparation

Endocrine Bioassays
Androgen Agonist/Antagonist Activity
  1. Immature castrated male rat model to evaluate test compound effects on androgen-dependent glands (ventral prostate, seminal vesicles) and muscle (levator ani)
  2. Duration of action of test compound in immature castrated male rat model
Estrogen Agonist/Antagonist Activity
  1. Immature female rat model to evaluate test compound effects on uterine weight and in selected assays, effects on uterine morphology (luminal epithelial cell height, endometrial width, myometrial width)
  2. Adult ovariectomized rat model to evaluate test compound effects on vaginal cornification with or without uterotrophic activity
Progestin Agonist/Antagonist Activity
  1. Immature female rabbit model to evaluate test compound effects on uterine weight and uterine histology based on the McPhail index; test compound may be administered by intrauterine route
Glucocorticoid Agonist/Antagonist Activity
  1. Adrenalectomized young male rat model to evaluate test compound effects on thymic involution

Safety and Drug Development Studies
  1. Polyclonal antiserum production in adult male rabbits, specialty steroid-conjugates
  2. Pharmacokinetic assays in rat, rabbit, or monkey - either sex by multiple routes
  3. Vaginal irritation assay in adult female rabbits
  4. Liver function/toxicity assay in adult male rabbits to evaluate test compound effects on clearance of BSP dye from the circulation and effects on serum liver enzymes
  5. Anti-tumorigenic assays in nude mice injected with human prostate or breast cancer cells, male or female, as appropriate to evaluate test compound effects on tumor progression
  6. Evaluation of test compounds for potential adverse effects on ovarian or testicular function
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Assays may be done under FDA/EPA GLP guidelines.

Steroid Receptor Binding Assays
  1. Rat androgen receptor ligand binding domain (ARLBD) for assessing affinity of androgen agonists and antagonists
  2. Human recombinant estrogen receptor (ER)A and B-1, long form, for assessing affinity of estrogen agonists and antagonists
  3. Human recombinant progesterone receptor (PR) A and B for assessing affinity of progestin agonists and antagonists
  4. Human recombinant glucocorticoid receptor (GR) for assessing affinity of glucocorticoid agonists and antagonists
  5. Binding assays involving rabbit cytosols: uterine PR or thymic GR
  6. Whole cell uptake assays for various radiolabeled steroids or other compounds
Transactivation Assays for Steroid Hormones or Synthetic Steroids using Luciferase Reporter Genes
  1. Androgen agonist/antagonist assays using CV-1 cells (African green monkey kidney) and a human AR expression vector
  2. Progestin agonist/antagonist assays using T47Dco human breast cancer cells
  3. Estrogen agonist/antagonist assays using T47Dco cells
  4. Glucocorticoid agonist/antagonist assays using HepG2 human hepatocellular carcinoma cells and a rat GR expression vector
  5. Mineralocorticoid agonist/antagonist assays using CV-1 cells and a human mineralocorticoid receptor (MR) expression vector
Other Cell-based Assays
  1. Stimulation/inhibition of alkaline phosphatase production in T47Dco cells (progestin agonist/antagonist assay)
  2. Stimulation/inhibition of Prostate Specific Antigen (PSA) production in prostate cancer cell lines (CWR22Rv1, LNCaP)
  3. Cytotoxicity assays: cell proliferation (MTS, Cell Counting Kit-8), cell viability (ATP, CellTiter-Blue), caspase 3/7 (apoptosis), membrane integrity (LDH)
  4. Induction of cytochrome P450 (CYP) 3A4 and 1A2
  5. Stimulation/inhibition of intracellular or secreted cyclic AMP (cAMP)
  6. Aromatization of various androgens
  7. Histamine release assay from rat peritoneal mast cells
Studies using primary cell cultures from rat testes
  1. Rat Sertoli cells
Radioimmunoassays (RIAs)
  1. Monkey, rat, rabbit LH and FSH
  2. Steroid hormones: estradiol, progesterone, corticosterone, cortisol, testosterone, dihydrotestosterone
  1. Inhibin B (monkey, rat)
  2. Prostate specific antigen (PSA) (monkey, human)
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