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Table 1 Model parameters treated as constants (n = 97)

From: A computational model of the hypothalamic - pituitary - gonadal axis in female fathead minnows (Pimephales promelas) exposed to 17α-ethynylestradiol and 17β-trenbolone

Parameter description Symbols Value Reference
Body weighta BodyWt 0.0016 (kg) Watanabe et al. [38]
Volumetric water flowing through gills FWgil 10.6× BodyWt 0.75 (L/hr) Nichols et al. [57]
Cardiac output Fcar 2.06× BodyWt 0.75 (L/hr) Nichols et al. [57]
Percentage of brain to body weight (BSI) Pbrn 1.18 Measured by D. Villeneuve
Percentage of gonads to body weight (GSI)b Pgon 11 Watanabe et al. [38]
Percentage of liver to body weight (HSI)c Pliv 3.0 Watanabe et al. [38]
Percentage of gills to body weight Pgil 1.67 Nichols et al. [58]
Percentage of venous blood to body weight Pven 2.59 Robinson et al. [59]
Nichols et al. [58]
Percentage of "other" to body weight Poth = 100- Pbrn- Pgon- Pliv- Pgil- Pven Watanabe et al. [20]
Fraction of blood flow in brain to cardiac output Nichols et al. [58]
Fraction of blood flow in gonad to cardiac output Nichols et al. [58]
Fraction of blood flow in liver to cardiac output Nichols et al. [58]
Fraction of blood flow in "other" to cardiac output Nichols et al. [58]
Fraction of plasma in venous blood Fplasma, ven 0.45 Measured by K. Kroll
Total concentration of estrogen receptors in brain CER, brn 14.3 (nmol/L tissue) Plowchalk and Teaguarden [60]
Total concentration of estrogen receptors in gonad CER, gon 29 (nmol/L tissue) Plowchalk and Teaguarden [60]
Total concentration of LH receptors in gonad CLR, gon 2.0 (nmol/L tissue) Miwa et al. [61]
Total concentration of SBP in blood CSBP, ven 400 (nmol/L blood) Laidley and Thomas[37]
Teeguarden and Barton [36]
Total concentration of AR in gonad CAR, gon 1.05 (nmol/L tissue) Sperry and Thomas [62]
Total concentration of AR in liver CAR, liv = CAR, gon assumed
Association rate of E2 to estrogen receptor in brain k 1_E2ER, brn 0.743 Murphy et al. [63]
Dissociation constant of E2 to estrogen receptor in gonad K d_E2ER, gon = Kd _E2ER, brn assumed
Association rate of E2 to estrogen receptor in gonad k 1_E2ER, gon = k1 _E2ER, brn assumed
Dissociation constant of E2 to estrogen receptor in liver K d_E2ER, liv = Kd _E2ER, brn assumed
Association rate of E2 to estrogen receptor in liver K 1_E2ER, liv = k1 _E2ER, brn assumed
Dissociation constant of EE2 to estrogen receptor in brain K d_EE2ER, brn = Kd _E2ER, brn/RBAEE2_E2 Denny et al. [15]
Association rate of EE2 to estrogen receptor in brain k 1_EE2ER, brn = k1 _E2ER, brn assumed
Dissociation constant of EE2 to estrogen receptor in gonad K d_EE2ER, gon = Kd _EE2ER, brn assumed
Association rate of EE2 to estrogen receptor in gonad k 1_EE2ER, gon = k1 _EE2ER, brn assumed
Dissociation constant of EE2 to estrogen receptor in liver K d_EE2ER, liv = Kd _EE2ER, brn assumed
Association rate of EE2 to estrogen receptor in liver k 1_EE2ER, liv = k1 _EE2ER, brn assumed
Dissociation constant of T to androgen receptor in brain K d_TAR, brn 3 (nmol/L) Sperry and Thomas [62]
Association rate of T to androgen receptor in brain k 1_TAR, brn 0.08 (L/nmol/hr) Sperry and Thomas [62]
Dissociation constant of T to androgen receptor in gonad K d_TAR, gon = Kd _TAR, brn assumed
Association rate of T to androgen receptor in gonad k 1_TAR, gon = k1 _TAR, brn assumed
Dissociation constant of T to androgen receptor in liver K d_TAR, liv = Kd _TAR, brn assumed
Association rate of T to androgen receptor in liver k 1_TAR, liv = k1 _TAR, brn assumed
Dissociation constant of TB to androgen receptor in brain K d_TBAR, brn = Kd _TAR, brn/RBA TB_T Wilson et al. [64]
Association rate of TB to androgen receptor in brain k 1_TBAR, brn = k1 _TAR, brn assumed
Dissociation constant of TB to androgen receptor in gonad K d_TBAR, gon = Kd _TBAR, brn assumed
Association rate of TB to androgen receptor in gonad k 1_TBAR, gon = k1 _TBAR, brn assumed
Dissociation constant of TB to androgen receptor in liver K d_TBAR, liv = Kd _TBAR, brn assumed
Association rate of TB to androgen receptor in liver k 1_TBAR, liv = k1 _TBAR, brn assumed
Dissociation constant of E2 to SBP in blood K d_E2SBP, ven 3.13 (nmol/L) Murphy et al. [63]
Association rate of E2 to SBP in blood k 1_E2SBP, ven 5.6687 (L/nmol/hr) Murphy et al. [63]
Dissociation constant of T to SBP in blood K d_TSBP, ven 4.89 (nmol/L) Murphy et al. [63]
Association rate of T to SBP in blood K 1_TSBP, ven 5.6687 (L/nmol/hr) Murphy et al. [63]
Dissociation constant of EE2 to SBP in blood K d_EE2SBP, ven 0.58 (nmol/L) Miguel-Queralt and Hammond [34]
Association rate of EE2 to SBP in blood k 1_EE2SBP, ven 5.6687 (L/nmol/hr) Murphy et al. [63]
Dissociation constant of LH to LH receptor in gonad K d_LHLR, gon 2.9 (nmol/L) Crim et al. [65]
Association rate of LH to LH receptor in gonad k 1_LHLR, gon 0.2 (L/nmol/hr) Watanabe et al. [20]
Scaling coefficient of Vmax of T production in gonad (= Vmax/bodyweight 0.75) sc_VmaxScc, gon 1.1e+05 (nmol/hr/kg body weight) Kashiwagi et al. [66];
Shikita and Hall [67]
K0.5 of T production in gonad K0.5Scc, gon 190 (nmol/L) Shikita and Hall [67]
Inhibition constant of T production by bound ER KT 0.016 Watanabe et al. [20]
Km of E2 production in gonad Kmaro, gon 9.6 (nmol/L) Zhao et al. [68]
Concentration of microsomal protein in gonads Dmp, gon 3100 (mg/L) Measured by D. Villeneuve
Ratio between the concentrations of microsoaml protein in gonads and brain Rhomp 0.174 Measured by D. Villeneuve
Scaling coefficient of Vmax of E2 production in brain (= Vmax/mass of microsomal protein in brain) sc_Vmaxaro, brn = 4.6× sc_Vmaxaro, gon Zhao et al. [68]
Km of E2 production in brain Kmaro, brn 9.6 (nmol/L) Zhao et al. [68]
Concentration of microsomal protein in brain Dmp, brn = Dmp, gon/Rhomp Measured by D. Villeneuve
Ratio between concentrations of STAR and bound LR in gonads RhoSTAR, gon 1 assumed
Rate constant for Vtg uptake into oocytes k vtg, gon 0.05 assumed
K0.5 of Vtg production in liver production K0.5Vtg, liv 1.0 (nmol/L) Watanabe et al. [20]
Elimination rate constant for ER
in the liver compartment
ke_ER, liv 0.01 (1/hr) Murphy et al. [63]
Elimination rate constant for AR
in the brain compartment
ke_AR, brn 0.01 (1/hr) Assumed
Elimination rate constant for LH
in the "other" compartment
ke_LH, oth 0.1 (1/hr) Teeguarden and Barton [36]
Elimination rate constant for E2
in the "other" compartment
ke_E2, oth 0.1 (1/hr) Teeguarden and Barton [36]
Elimination rate constant for T
in the "other" compartment
ke_T, oth 0.1 (1/hr) Teeguarden and Barton [36]
Elimination rate constant for EE2
in the "other" compartment
ke_EE2, oth 0.1 (1/hr) Teeguarden and Barton [36]
Elimination rate constant for TB
in the "other" compartment
ke_TB, oth 0.1 (1/hr) Teeguarden and Barton [36]
Elimination rate constant for Vtg
in the "other" compartment
ke_Vtg, oth 0.001 (1/hr) Teeguarden and Barton [36]
Partition coefficient of LH
(brain to blood)
λ LH, brn 1 Teeguarden and Barton [36]
Partition coefficient of LH
(gonad to blood)
λ LH, gon 1 Teeguarden and Barton [36]
Partition coefficient of LH
(liver to blood)
λ LH, liv 1 Teeguarden and Barton [36]
Partition coefficient of LH
("other" to blood)
λ LH, oth 1 Teeguarden and Barton [36]
Partition coefficient of VTG
(brain to blood)
λ VTG, brn 1 Teeguarden and Barton [36]
Partition coefficient of VTG
(gonad to blood)
λ VTG, gon 1 Teeguarden and Barton [36]
Partition coefficient of VTG
(liver to blood)
λ VTG, liv 1 Teeguarden and Barton [36]
Partition coefficient of VTG
("other" to blood)
λ VTG, oth 1 Teeguarden and Barton [36]
Partition coefficient of EE2
(blood to water)
λ EE2, bld 300 Watanabe et al. [20]
Partition coefficient of EE2
(brain to blood)
λ EE2, brn 1 Teeguarden and Barton [36]
Partition coefficient of EE2
(gonad to blood)
λ EE2, gon 1 Teeguarden and Barton [36]
Partition coefficient of EE2
(liver to blood)
λ EE2, liv 3 Watanabe et al. [20]
Partition coefficient of EE2
("other" to blood)
λ EE2, oth 1 Teeguarden and Barton [36]
Partition coefficient of E2
(blood to water)
λ E2, bld 300 Watanabe et al. [20]
Partition coefficient of E2
(brain to blood)
λ E2, brn 1 Teeguarden and Barton [36]
Partition coefficient of E2
(gonad to blood)
λ E2, gon 1 Plowchalk and Teeguarden [60]
Partition coefficient of E2
(liver to blood)
λ E2, liv 3 Watanabe et al. [20]
Partition coefficient of E2
("other" to blood)
λ E2, oth 1 Plowchalk and Teeguarden [60]
Partition coefficient of T
(brain to blood)
λ T, brn 1 Barton and Andersen [69]
Partition coefficient of T
(gonad to blood)
λ T, gon 1 Barton and Andersen [69]
Partition coefficient of T
(liver to blood)
λ T, liv 1 Barton and Andersen [69]
Partition coefficient of T
("other" to blood)
λ T, oth 1 Barton and Andersen [69]
Partition coefficient of TB
(brain to blood)
λ TB, brn 1 Barton and Andersen [69]
Partition coefficient of TB
(gonad to blood)
λ TB, gon 1 Barton and Andersen [69]
Partition coefficient of TB
(liver to blood)
λ TB, liv 1 Barton and Andersen [69]
Partition coefficient of TB
("other" to blood)
λ TB, oth 1 Barton and Andersen [69]
  1. a, b, and c were assigned with measured values in each fish; the default values were used only when measured data were missing.