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Table 1 Model parameters and initial conditions

From: Mathematical modeling and analysis of insulin clearance in vivo

Parameter Value Source Meaning of the parameter
kins 10-3 nM-1 s-1 [36] insulin binding to the receptor
kins 1d 4·10-4 s-1 [36] insulin dissociation from the receptor (I1, PM)
kins 2d 4·10-2 s-1 [36] insulin dissociation from the receptor (I2, PM)
kins 1den 1.925·10-3 s-1 [49] insulin dissociation from the receptor (I1, EN)
kins 2den 3.85·10-3 s-1 [50] insulin dissociation from the receptor (I2, EN)
kyd 3.85·10-3 s-1 [51] receptor dephosphorylation (PM)
kyden 7.22·10-3 s-1 [52] receptor dephosphorylation (EN)
kyp 0.0231 s-1 [52] autophosphorylation of the receptor (I1 and I2)
intk 1 5.5·10-4 s-1 [34] internalization of phosphorylated receptors
intk 2 2·10-4 s-1 [34] internalization of unphosphorylated receptors
reck 1 1.533·10-3 s-1 [34] recycling of receptors without insulin
k 1ub 0.35 s-1 [46] nonspecific insulin binding in the liver
k 2ub 0.2 s-1 [46] dissociation of nonspecifically bound insulin
pansec 0.0016976 nM·s-1 calc. pancreatic insulin secretion
K pan 0.5 nM ass. concentration of half-maximal insulin secretion
m liver 0.05·m body [46] mass of the liver
v p 0.03375·10-3 l·g-1·m body [54] plasma volume
ρ liver 1.051·103l-1 [53] density of the liver
v hep (m liver /ρ liver )·0.78 [45] total hepatocyte volume
v d 0.272·10-3 l·g-1·v hep ·ρ liver [46] volume of the space of Disse
m kidney 2·0.85 g·mbody/(230 g) [55] mass of the kidney
K kidney 0.0225·10-3 l·(s·g)-1·m kidney [47] clearance of the kidney
  1. Note that m body (body weight in g), t in (injection time in s), n in and n*,in(amounts of injected unlabeled and labeled insulin in nmol) are also model parameters. We do not give values for them in this table as they depend on the analyzed scenario. Note that the model can be used for rats of arbitrary body weights as well as for different injection times and amounts of injected labeled and unlabeled insulin. Initial conditions are: Ins = 0.07, Ins* = 0, R = 31.619, IR = 0.430007, I 2R = 0.000696311, Rp = 0.227528, IRp = 2.07275, I 2Rp = 0.00363012, R en = 4.88528, IR en = 0.145537, I 2R en = 0.000121295, Rp en = 0.122602, IRp en = 0.492464, I 2Rp en = 0.000433466, Ins ub = 1.29948·10-6·m body , Ins*,ub= 0. The unit of Ins ub and Ins*,ubis nmol, the unit of all other state variables is nM. ass.: assumption, calc.: calculation (see Additional file 4), EN: in endosomes, PM: at the plasma membrane, I 1: one insulin molecule bound to the receptor, I 2: two insulin molecules bound to the receptor.