Table 2.
Calculated flux distribution during defatting period (µmol/106 cells/day).*
| Stoichiometry | Rxn Number | Lean Normoxia | DMEM Normoxia | Defat Normoxia | Defat Hyperoxia |
|---|---|---|---|---|---|
| Glycolysis | |||||
| Glucose + ATP --> G-6-P | 1 | 0.010 ± 0.001 | −0.002 ± 0.000 | 0.001 ± 0.000 | 0.001 ± 0.000 |
| G-6-P --> F-6-P | 2 | 0.013 ± 0.002 | 0.128 ± 0.009 | 0.212 ± 0.011 | 0.242 ± 0.059 |
| F-6-P + ATP --> Glyceraldehyde-3-P + DHAP | 3 | 0.013 ± 0.002 | 0.128 ± 0.009 | 0.212 ± 0.011 | 0.242 ± 0.059 |
| DHAP --> Glyceraldehyde-3-P | 4 | 0.013 ± 0.002 | 0.128 ± 0.009 | 0.212 ± 0.011 | 0.242 ± 0.059 |
| Glyceraldehyde-3-P --> 3-PGA | 5 | −0.036 ± 0.005 | 0.306 ± 0.021 | 0.488 ± 0.025 | 0.505 ± 0.128 |
| 3PGA --> PEP + NADH + 2ATP | 6 | −0.036 ± 0.005 | 0.306 ± 0.021 | 0.488 ± 0.025 | 0.505 ± 0.128 |
| PEP --> Pyruvate | 7 | −0.036 ± 0.005 | 0.306 ± 0.021 | 0.488 ± 0.025 | 0.505 ± 0.128 |
| Pyruvate + NADH --> Lactate | 8 | −0.015 ± 0.001 | −0.001 ± 0.000 | 0.002 ± 0.000 | 0.005 ± 0.001 |
| Pyruvate --> Acetyl-CoA + NADH +CO2 | 9 | −0.021 ± 0.005 | 0.307 ± 0.021 | 0.486 ± 0.025 | 0.500 ± 0.128 |
| TCA Cycle | |||||
| Acetyl-CoA + OAA --> Citrate | 10 | 0.033 ± 0.010 | 0.909 ± 0.066 | 1.491 ± 0.079 | 1.709 ± 0.414 |
| Citrate --> alpha-KG + NADPH +CO2 | 11 | 0.033 ± 0.010 | 0.909 ± 0.066 | 1.491 ± 0.079 | 1.709 ± 0.414 |
| alpha-KG --> Succinyl-CoA + NADH + CO2 | 12 | 0.034 ± 0.010 | 0.911 ± 0.066 | 1.492 ± 0.079 | 1.710 ± 0.414 |
| Succinyl-CoA --> Fumarate + FADH2 + ATP | 13 | 0.034 ± 0.010 | 0.911 ± 0.066 | 1.492 ± 0.079 | 1.710 ± 0.414 |
| Fumarate --> OAA + NADH | 14 | 0.033 ± 0.010 | 0.909 ± 0.066 | 1.491 ± 0.079 | 1.709 ± 0.414 |
| Pentose Phosphate Pathway and Glycogen Metabolism | |||||
| (Glucose)n-1 + G-6-P --> (Glucose)n | 15 | −0.004 ± 0.001 | −0.129 ± 0.009 | −0.212 ± 0.011 | −0.241 ± 0.059 |
| G-6-P --> 12 NADPH + 6 CO2 | 16 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Ketone Body Production | |||||
| 2 Acetyl-COA --> Acetoacetyl-CoA | 17 | −0.002 ± 0.000 | 0.001 ± 0.001 | 0.005 ± 0.001 | 0.007 ± 0.002 |
| Acetoacetyl-CoA --> Acetoacetate | 18 | −0.001 ± 0.000 | 0.002 ± 0.001 | 0.006 ± 0.001 | 0.008 ± 0.002 |
| Acetoacetate Out | 19 | 0.000 ± 0.000 | 0.001 ± 0.000 | 0.003 ± 0.001 | 0.004 ± 0.001 |
| Acetoacetate + NADH --> B-OH butyrate | 20 | 0.000 ± 0.000 | 0.001 ± 0.000 | 0.003 ± 0.001 | 0.004 ± 0.001 |
| Oxidative Phosphorylation | |||||
| Oxygen In | 21 | 0.004 ± 0.002 | 0.004 ± 0.002 | 0.004 ± 0.002 | 0.022 ± 0.007 |
| NADH + 0.5 O2 --> 2.5 ATP | 22 | 0.014 ± 0.019 | 1.641 ± 0.118 | 2.686 ± 0.141 | 3.059 ± 0.738 |
| FADH2 + 0.5 O2 --> 2 ATP | 23 | 0.035 ± 0.010 | 0.912 ± 0.066 | 1.493 ± 0.079 | 1.711 ± 0.414 |
| Glycerol and Fatty Acid Metabolism | |||||
| Glycerol + ATP --> Glycerol-3-P | 24 | −0.063 ± 0.002 | 0.030 ± 0.004 | 0.027 ± 0.004 | −0.023 ± 0.009 |
| Glycerol-3-P --> Glyceraldehyde-3-P + NADH | 25 | −0.063 ± 0.002 | 0.050 ± 0.004 | 0.064 ± 0.004 | 0.021 ± 0.014 |
| FA-CoA --> 8(9) Acetyl-CoA + 14(16) NADH | 26 | 0.006 ± 0.001 | 0.067 ± 0.005 | 0.113 ± 0.006 | 0.136 ± 0.032 |
| FA-CoA + DAG --> TG | 27 | −0.001 ± 0.000 | −0.020 ± 0.002 | −0.036 ± 0.002 | −0.044 ± 0.011 |
| Amino Acid Metabolism | |||||
| Ser In | 28 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Ser --> NH3 + Pyr | 29 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Gln In | 30 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| His --> Glu + NH4+ | 31 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Asp In | 32 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Glu In | 33 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Gly In | 34 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Gly --> 2 CO2 + NH3 + NADH + THF + ATP | 35 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| NH4+ In | 36 | −0.003 ± 0.000 | −0.003 ± 0.001 | −0.003 ± 0.001 | 0.001 ± 0.000 |
| Arg In | 37 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Thr --> Pyr + CO2 + NH4+ + 2 NADH + FADH2 | 38 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Ala In | 39 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Glu + Pyr --> Ala + aKG | 40 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Pro In | 41 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Cys In | 42 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Tyr In | 43 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Tyr + aKG + 2 O2 --> Glu + CO2 + Acetoacetate + Fumarate | 44 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Val + aKG --> Glu + CO2 + 2NADH + FADH2 + Succ-CoA | 45 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Orn In | 46 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Lys + 2 aKG + NADPH --> 2Glu + Acetoacetyl-CoA + 2CO2 + 4 NADH + FADH2 | 47 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Ile + aKG --> Glu + Succ-CoA + Acetyl-CoA + NADH + FADH2 | 48 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Leu + aKG --> Glu + Acetyl-CoA + Acetoacetate + CO2 + NADH + FADH2 | 49 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Phe + O2 --> Tyr | 50 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Glu + Cys + Gly --> GSH | 51 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Urea Cycle | |||||
| HCO3- + NH4+ + Orn + 2 ATP --> Citrulline | 52 | −0.002 ± 0.000 | −0.002 ± 0.000 | −0.002 ± 0.000 | −0.002 ± 0.000 |
| Citrulline + Asp + ATP --> Fumarate + Arginine | 53 | −0.002 ± 0.000 | −0.002 ± 0.000 | −0.002 ± 0.000 | −0.002 ± 0.000 |
| Arginine --> Orn + Urea | 54 | 0.023 ± 0.014 | 1.276 ± 0.092 | 2.089 ± 0.110 | 2.366 ± 0.576 |
| Urea Out | 55 | −0.013 ± 0.007 | −0.638 ± 0.046 | −1.046 ± 0.055 | −1.182 ± 0.288 |
| Orn + alpha-KG + 0.5 NADPH + 0.5 NADH --> Pro | 56 | 0.001 ± 0.000 | 0.001 ± 0.000 | 0.001 ± 0.000 | 0.001 ± 0.000 |
| Amino Acid Metabolism (Cont’d) | |||||
| Gln --> Glu + NH4+ | 57 | 0.015 ± 0.015 | 1.267 ± 0.092 | 2.083 ± 0.110 | 2.407 ± 0.576 |
| Asp + NH4+ --> Asn | 58 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Thr --> Pyr + CO2 + NH4+ + 2 NADH + FADH2 | 59 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Val + aKG --> Glu + CO2 + 2NADH + FADH2 + Succ-CoA | 60 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Lys + 2 aKG + NADPH --> 2Glu + Acetoacetyl-CoA + 2CO2 + 4 NADH + FADH2 | 61 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Ile + aKG --> Glu + Succ-CoA + Acetyl-CoA + NADH + FADH2 | 62 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Leu + aKG --> Glu + HMG-CoA + NADH + FADH2 | 63 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Phe + O2 --> Tyr | 64 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Phospholipid, Sphingolipid, and Cholesterol Metabolism | |||||
| Ser + 1 Palm-CoA + 1 FA-CoA + NADPH --> Ceramide + CO2 + FADH2 | 65 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Ceramide + Phosphatidylcholine --> Sphingomyelin | 66 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Acetoacetyl-CoA + Acetyl-CoA --> HMG-CoA | 67 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| HMG-CoA + 2 NADPH (+ 3ATP) --> IPP | 68 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| 2 IPP --> Geranyl-PP | 69 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Geranyl-PP + IPP --> Farnesyl-PP | 70 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| 2 Farnesyl-PP + 0.5 NADPH + 0.5 NADH --> Squalene | 71 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Squalene + O2 + NADPH --> Lanosterol | 72 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Lanosterol + 10.5 NADPH + 4.5 NADH + 10 O2 --> Chol + 3 CO2 | 73 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Cholesterol Ester --> Chol + FA-CoA | 74 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| 2 FA-CoA + Glycerol-3-P --> Phosphatidate | 75 | −0.001 ± 0.000 | −0.020 ± 0.002 | −0.036 ± 0.002 | −0.044 ± 0.011 |
| Phosphatidate --> DAG | 76 | −0.001 ± 0.000 | −0.020 ± 0.002 | −0.036 ± 0.002 | −0.044 ± 0.011 |
| Phosphatidate --> CDP-DAG | 77 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| CDP-DAG + Ser --> PhosphatidylSerine | 78 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| PhosphatidylSerine --> PhosphatidylEthanolamine + CO2 | 79 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| CDP-DAG + G-3-P --> PhosphatidylGlycerol | 80 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| 2 PG --> Cardiolipin + Glycerol | 81 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| DAG + CDP-Choline --> PhosphatidylCholine | 82 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| DAG + CDP-Ethanolamine --> PhosphatidylEthanolamine | 83 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Cholesterol Out | 84 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 | 0.000 ± 0.000 |
| Polyamine and NADPH | |||||
| Arg --> Putrescine + 2 CO2 + 2 NH3 | 85 | 0.011 ± 0.007 | 0.637 ± 0.046 | 1.045 ± 0.055 | 1.181 ± 0.288 |
| Arg --> Putrescine + CO2 + Urea | 86 | −0.036 ± 0.022 | −1.914 ± 0.138 | −3.134 ± 0.165 | −3.548 ± 0.864 |
| Putrescine + alpha-KG + O2 --> NH3 + NADH + Glu + NADPH + Succinate | 87 | −0.022 ± 0.015 | −1.273 ± 0.092 | −2.087 ± 0.110 | −2.364 ± 0.576 |
| Putrescine + 2 alpha-KG --> 1.5 NADH + 2 Glu + 0.5 NADPH + Succinate | 88 | −0.003 ± 0.000 | −0.004 ± 0.002 | −0.003 ± 0.002 | −0.003 ± 0.001 |
| Glu + 2 NADPH --> Pro | 89 | −0.025 ± 0.015 | −1.278 ± 0.092 | −2.090 ± 0.110 | −2.367 ± 0.576 |
| FA --> FA-CoA | 90 | 0.003 ± 0.000 | 0.007 ± 0.002 | 0.004 ± 0.002 | 0.003 ± 0.001 |
| 8 Acetyl-CoA + 14 NADPH --> Palm-CoA | 91 | −0.001 ± 0.000 | −0.020 ± 0.002 | −0.036 ± 0.002 | −0.044 ± 0.011 |
* data shown are averages of n = 3 experiments ± S.E.M. A negative value indicates flux is in the opposite direction of that shown in Figure 6.