. Author manuscript; available in PMC: 2020 Apr 20.

Published in final edited form as: J Pharmacokinet Pharmacodyn. 2018 Apr 27;45(4):557–575. doi: 10.1007/s10928-018-9585-x

Table 3.

Parameter estimates for phosphoenolpyruvate carboxykinase (PEPCK) regulation and glucose homeostasis

Parameter (units)	Definition	Estimate (% CV)
CCAAT enhancer binding protein-β mRNA dynamics
k_d,C/EBP-βm (h⁻¹)	Degradation rate constant for C/EBP-β mRNA	3.2 (35.0)
$S_{D R n}^{C / E B P - β m} ({nM}^{- 1})$	Stimulation constant for C/EBP-β mRNA synthesis	0.0038 (13.9)
C/EBP-β_m (0)	Baseline C/EBP-β mRNA	0.96 (3.9)
Phosphoenolpyruvate carboxykinase mRNA and Protein Dynamics
k_GMD (h⁻¹)	First-order rate constant for GMD signal	0.42 (20.3)
k_d,PEPCKm (h⁻¹)	Degradation rate constant for PEPCK mRNA	0.053 (53.7)
$S_{D R n}^{PEPC K m} ({nM}^{- 1})$	Stimulation constant for PEPCK mRNA synthesis	0.17 (63.1)
$S_{GMD}^{PEPC K m} ({nM}^{- 1})$	Stimulation constant for PEPCK mRNA degradation	0.27 (59.8)
k_d,PEPCK (h⁻¹)	Degradation rate constant for PEPCK protein	0.3 (41.9)
γ	Power coefficient for PEPCK translation from mRNA	0.0048 (fixed)
k_CREB (h⁻¹)	First-order rate constant for CREB signal	2.77 (fixed)
$S_{CREB}^{PEPC K} ({nM}^{- 1})$	Stimulation constant for PEPCK protein - CREB	0.004 (32.9)
$S_{C / E B P}^{PEPC K} ({nM}^{- 1})$	Stimulation constant for PEPCK protein - C/EBP-β	0.001 (fixed)
PEPCK_m (0) (fmol/g)	Baseline PEPCK mRNA	209
PEPCK (0)	Baseline PEPCK protein	0.98 (8.6)
Plasma glucose and insulin dynamics
k_d,Gluc (h⁻¹)	Degradation rate constant for glucose	1.48 (fixed)
$S_{PEPC K}^{Gluc} ({nM}^{- 1})$	Stimulation constant for glucose synthesis by PEPCK	0.33 (17.8)
$S_{I n s}^{Gluc} {(ng/mL)}^{- 1}$	Insulin sensitivity	0.043 (77.2)
K_d,Ins (h⁻¹)	Degradation rate constant for insulin	0.049 (55.3)
$S_{Gluc}^{I n s} {(mg/dL)}^{- 1}$	Glucose sensitivity	0.5 (47.5)
Glucose (0) (mg/dL)	Baseline plasma glucose concentration	148
Insulin (0) (ng/mL)	Baseline plasma insulin concentration	0.24