Skip to main content

Table 1 Explanation of measured receptor transactivities induced by amniotic fluid (AF) and receptor ligand equivalent calculation

From: Autism spectrum disorders, endocrine disrupting compounds, and heavy metals in amniotic fluid: a case-control study

Abbreviations Explanation Example of calculation
ER-tact Luciferase reporter gene transactivity of estrogen receptor (ER)  
ER-EEQ The combined effect on ER induced by the combination of endogenous estrogen and xeno-estrogens (EDCs) given as estradiol equivalent • ER-tact of AF: 2.51
• Interpolation of ER-tact onto E2 dose-response curve
• ER-EEQ = 247.60 pg E2/ml AF
EDC-EEQ The integrated estrogenic effect induced by xeno-estrogens (EDCs) alone given as estradiol equivalent • Endogenous E2: 230.23 pg/ml
• (ER-EEQ) − E2 = 247.60 − 230.32 = 17.28 E2 pg/ml AF
AR-tact Luciferase reporter gene transactivity of androgen receptor (AR)  
AR-AEQ The combined effect on AR induced by the combination of endogenous androgens and xeno-androgens (EDCs) given as androgen equivalent • AR-tact of AF: 3.30
• Interpolation of AR-tact onto DHT dose-response curve
• AR-AEQ = 63.50 pg DHT/ml AF
EDC-AEQ The integrated androgenic effect induced by xeno-androgens (EDCs) alone given as androgen equivalent • Testosterone: 470.12 pg/ml AF
• DHT: estimated DHT = 10% × 470.12 = 47.01 pg/ml AF
• (AR-AEQ) − DHT = 63.50 − 47.01 = 16.49 pg DHT/ml AF
AR-AEQ/ER-EEQ The proportion of total combined androgenic effect to the total combined estrogenic effect • AR-AEQ = 63.50 pg DHT/mlAF
• ER-EEQ = 247.60 pg E2/mlAF
• AR-AEQ/ER-EEQ = 63.50/247.60 = 0.256
EDC-AEQ/EDC-EEQ The proportion of EDC-induced androgenic effect to EDC-induced estrogenic effect • EDC-AEQ = 16.49 DHT/mlAF
• EDC-EEQ = 17.28 E2/mlAF
• EDC-AEQ/EDC-EEQ = 16.49/17.28 = 0.954
TH-PE Thyroid hormone-related proliferative effect  
T3-ThEQ The combined proliferation effect (PE) of endogenous thyroid hormone and xeno-thyroid hormone-like compounds (EDCs) given as thyroid equivalent • TH-PE of AF: 4.56
• Interpolation of TH-PE onto T3 dose-response curve
• T3-ThEQ = 3.53 ng T3/ml AF
AhR-tact Luciferase reporter gene transactivity of aryl hydrocarbon receptor (AhR)  
AhR-TEQ The combined effect on AhR of dioxin-like compounds given as TCDD equivalent • AhR-tact of AF extraction: 5.67
• AhR-tact of blank: 4.75
• Interpolation of AhR-tact onto TCDD dose-response curve = AhR-TEQ
• AhR-TEQ of AF extraction = 1.46 pg TCDD/ml,
• AhR-TEQ of blank = 1.22 pg TCDD/ml
• Final AhR-TEQ = 1.46 − 1.22 = 0.24 pg TCDD/ml AF
  1. AF amniotic fluid, AEQ androgen equivalent, AR androgen receptor, AhR aryl hydrocarbon receptor, DHT dihydrotestosterone, EDCs endocrine disrupting compounds, EEQ estradiol equivalent, ER estrogen receptor, E2 17 β-Estradiol, PE proliferation effect, TCDD 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin, TEQ TCDD equivalent, T3 triiodothyronine, ThEQ thyroid equivalent