Table 2. HPOL model parameters, values and sensitivity ranking (sens.).
Parameter | Value | Units | Function | Source | Sens. |
---|---|---|---|---|---|
Pituitary | |||||
ks,mFSH | 0.05895 | (pg/μg RNA)/hr | Rate of mFSH synthesis | [45]2,6 | 67 |
αmFSH,GnRH | 2.0917 | unitless | Stimulatory factor on mFSH synthesis due to GnRH | [46]2,6 | 44 |
kd,mFSH | 0.2446 | hr-1 | Rate of mFSH degradation | Eq (7) and optimized around mFSH data.6 | 48 |
ks,mLH | 0.0512 | (pg/μg RNA)/hr | Rate of mLH synthesis | Assumed to be within ±25% of ks,mFSH.6 | 45 |
αmLH,GnRH | 0.01 | unitless | Stimulatory factor on mLH synthesis due to GnRH | [47] | 23 |
αmLH,E2 | 4.15 | ml/ng | Stimulatory factor on mLH synthesis due to E2 | [45]2,6 | 56 |
kd,mLH | 0.1046 | hr-1 | Rate of mLH degradation | Used E2 data from [41].4,6 | 66 |
ks,LH | 1.004 | (pg/μg RNA)-1 ng/mg pituitary/hr | Rate of LH synthesis | Used E2 data from [41] and DHP and mLH from our experiment.4,6 | 58 |
kd,LH | 0.06 | hr-1 | Rate of LH degradation | Used E2 data from [41] and DHP and mLH from our experiment.4,6 | 46 |
kr,LH | 66700 | hr-1 | Rate of LH release from the pituitary into the blood | Used E2 data from [41] and DHP and mLH from our experiment.4,6 | 9 |
TE2,LH | 23 | ng/ml | Threshold value for E2 levels that allow LH release from the pituitary into the plasma | [48]2,6 | 39 |
nE2 | 9 | unitless | Determines the range of E2 levels that allow for LH release from the pituitary into the plasma | Used E2 data from [41] and DHP and mLH from our experiment.4,6 | 21 |
NE2 | 36.78 | ml/mg pituitary | Conversion factor of E2 to the minimum amount of D2r needed to maintain the block on LH release | Used E2 data from [41] and DHP and mLH from our experiment.4,6 | 42 |
NDHP | 2.8 | ml/mg pituitary | Conversion factor of DHP to the minimum amount of D2r needed to maintain the block on LH release | Used E2 data from [41] and DHP and mLH from our experiment.4,6 | 22 |
wPit | 15 | mg/kg | Pituitary weight | Directly measured | 71 |
Plasma | |||||
VFSH | 156 | ml/kg | FSH volume of distribution | [49,50]2, 6 | 20 |
ks,FSH | 0.0138 | (pg/μg RNA)-1 ng/mg pituitary/hr | Rate of appearance of FSH in the blood | [45]2,6 | 61 |
ClFSH | 1.7372 | ml/hr/kg | FSH clearance | [49]2,6 | 63 |
VLH | 156 | ml/kg | LH volume of distribution | Assumed to be equal to FSH, based on [49,50] | 7 |
ClLH | 1.7372 | ml/hr/kg | LH clearance | Assumed to be equal to FSH | 14 |
VE2 | 261 | ml/kg | E2 volume of distribution | [51]1 | 12 |
ClE2 | 22 | ml/hr/kg | E2 clearance | [51]1 | 75 |
VDHP | 261 | ml/kg | DHP volume of distribution | Assumed to be equal to E2 | 19 |
ClDHP | 57 | ml/hr/kg | DHP clearance | Assumed from observed data.2,6 | 33 |
240 | ml/kg | Plasma VTG volume of distribution | [52]1 | 29 | |
ClVTG,trans | 42.2 | ml/hr/kg | Intercompartmental clearance between central and peripheral | [52]1 | 26 |
ClVTG,Seq | 170 | ml/hr/kg | Clearance of VTG from blood due to uptake by the ovaries | [12]2,6 | 31 |
TSeq,FSH | 13.7 | ng/ml | Threshold value for FSH effect on VTG uptake by the ovaries | [36]2,6 | 15 |
ClVTG | 29.3 | ml/hr/kg | Total body clearance of VTG | [52]1 | 32 |
318 | ml/kg | Volume of distribution of VTG in peripheral tissues | [52]1 | 17 | |
Ovary | |||||
kE2 | 0.0053 | ng/hr/ follicle | Rate of E2 basal production | [53]2,6 | 38 |
noocyte | 2500 | follicle/kg | Number of oocyte follicles per kg of fish | [38]2 | 59 |
0.00057 | ml/hr/ follicle | Clearance of E2 from the follicle due to stimulation by FSH in stage 2 | Used FSH data from our experiment.4,6 | 16 | |
0.00057 | ml/hr/ follicle | Clearance of E2 from the follicle due to stimulation by FSH in stage 3 | Used FSH data from our experiment.4,6 | 35 | |
0.0027 | ml/hr/ follicle | Clearance of E2 from the follicle due to stimulation by FSH in stage 4 | Used FSH data from our experiment.4,6 | 50 | |
0.0561 | ml/hr/ follicle | Clearance of E2 from the follicle due to stimulation by FSH in stage 5 | Used FSH data from our experiment.4,6 | 49 | |
0.0617 | ml/hr/ follicle | Clearance of E2 from the follicle due to stimulation by FSH in stage 6 | Used FSH data from our experiment.4,6 | 28 | |
0.0003 | ml/hr/ follicle | Clearance of DHP from the follicle due to stimulation by LH in stage 2 | Used LH data from our experiment.4,6 | 11 | |
0.0003 | ml/hr/ follicle | Clearance of DHP from the follicle due to stimulation by LH in stage 3 | Used LH data from our experiment.4,6 | 24 | |
0.0003 | ml/hr/ follicle | Clearance of DHP from the follicle due to stimulation by LH in stage 4 | Used LH data from our experiment.4,6 | 18 | |
0.0003 | ml/hr/ follicle | Clearance of DHP from the follicle due to stimulation by LH in stage 5 | Used LH data from our experiment.4,6 | 27 | |
0.3 | ml/hr/ follicle | Clearance of DHP from the follicle due to stimulation by LH in stage 6 | Used LH data from our experiment.4,6 | 4 | |
0.79 | ml/hr/ follicle | Clearance of DHP from the follicle due to stimulation by LH in FOM | Used LH data from our experiment.4,6 | 3 | |
0.00067 | mm/hr/kg | Growth rate of individual non-vitellogenic follicles | [53]2,6 | 55 | |
2.19e-7 | mm/mg | Growth rate per amount of VTG sequestered by an individual follicle | Used VTG data from [45] and FSH data from our experiment.4,6 | 25 | |
0.0214 | mm2 | Maximal variance of follicles in stage 1 | [38]2,6 | 5 | |
0.0433 | mm2 | Maximal variance of follicles in stage 2 | [38] 2,6 | 6 | |
0.0748 | mm2 | Maximal variance of follicles in stage 3 | [38] 2,6 | 40 | |
0.0907 | mm2 | Maximal variance of follicles in stage 4 | [38] 2,6 | 57 | |
0.0338 | mm2 | Maximal variance of follicles in stage 5 | [38] 2,6 | 36 | |
0.014 | mm2 | Maximal variance of follicles in stage 6 | [38] 2,6 | 2 | |
0.0067 | mm2 | Maximal variance of the follicles in FOM | [38] 2,6 | 8 | |
s1 | 0.2 | mm | Follicle diameter dividing stages 1 and 2 (follicles are able to produce E2) | [5]1 | 13 |
s2 | 0.6 | mm | Follicle diameter dividing stages 2 and 3 (follicles are able to take up VTG) | [37]1 | 68 |
s3 | 1.17 | mm | Follicle diameter dividing stages 3 and 4 (follicles enter the mid-vitellogenic stage) | Used the data from our experiment and [41].6 | 69 |
s4 | 1.69 | mm | Follicle diameter dividing stages 4 and 5 (follicles enter the late vitellogenic stages) | Used the data from our experiment and [41].6 | 74 |
s5 | 3.4 | mm | Follicle diameter dividing stages 5 and 6 (follicles are able to produce substantially more DHP) | Used the data from our experiment and [41].6 | 62 |
s6 | 5.3 | mm | Follicle diameter dividing stages 6 and FOM (follicles are no longer able to sequester VTG) | Based on [5]: (s6-s2)/OM = 0.84, where OM is the maximum average oocyte diameter from [41] | 10 |
FOMfinal | 0.98 | unitless | Proportion of follicles in FOM needed before ovulation | Assumed6 | 30 |
DHPfinal | 120 | ng/ml | Concentration of DHP needed before ovulation can occur | Assumed based on DHP levels from present experiment.6 | 1 |
Liver | |||||
wL | 15 | g/kg | Liver weight | [12]3 | 41 |
ks,mR | 30 | pg/ug RNA/hr | Rate of mR synthesis | [12]3 | 78 |
αmR,ER | 0.0667 | g liver/ fmol | Maximal stimulatory fold-increase in mR synthesis due to ER complex | [12]3 | 65 |
kd,mR | 0.5 | hr-1 | Rate of mR degradation | [12]3 | 73 |
ks,R | 0.0113 | (pg/ug RNA)-1 fmol/g liver/hr | Rate of R synthesis | [12]3 | 76 |
kd,R | 0.466 | hr-1 | Rate of R degradation | [12]3 | 52 |
kon,ER | 0.826 | (ng/ml)-1 hr-1 | Association rate constant for ER | [12]3 | 60 |
koff,ER | 0.347 | hr-1 | Dissociation rate constant for ER | [12]3 | 64 |
kd,ER | 0.0766 | hr-1 | Rate of ER complex degradation | [12]3 | 77 |
ks,mVTG | 6.93E-05 | pg/ug RNA/hr | Rate of mVTG synthesis | [12]3 | 70 |
αmVTG,ER | 5.456e6 | g liver/ fmol | Stimulatory factor on VTG synthesis due to ER complex | [12]3 | 72 |
kd,mVTG | 0.00462 | hr-1 | Rate of mVTG degradation | [12]3 | 54 |
ks,VTG | 9.02E-06 | mg/g liver/hr | Rate of VTG synthesis | [12]2,6 | 53 |
NmVTG | 1000 | pg/ug RNA | Scaling factor for mVTG concentration | [12]3 | 47 |
γ | 2.48 | unitless | Amplification factor on the translation of VTG | [12]3 | 79 |
kr,VTG | 7.87 | hr-1 | Rate of VTG release from the liver into the plasma | [12]3 | 43 |
Transit Compartments | |||||
DFSH,E2 | 875 | hr | Delay of E2 synthesis due to FSH | Used FSH data from our experiment and E2 data from [41].5,6 | 51 |
DE2,mLH | 240 | hr | Delay of mLH synthesis due to E2 | Used E2 data from [41] and mLH data from our experiment.5,6 | 37 |
DLH,DHP | 72 | hr | Delay of DHP synthesis due to LH | Used LH data and DHP data from our experiment.5,6 | 34 |
1 Parameter value was obtained directly from source.
2 Guided initial estimates of the parameter value.
3 Parameter value was obtained from prior modeling efforts.
4 Specified data was used to create an input curve and an initial estimate was obtained through optimization methods solving a minimum number of differential equations.
5 Initial estimate was obtained by calculating time delays in the relative extrema from specified data.