Table 2.
k3 (min−1) | Fe | |||
---|---|---|---|---|
Sheep # | Control | Smoke | Control | Smoke |
Sheep s1 | 0.019 | 0.025 | 0.214 | 0.213 |
Sheep s2 | 0.010 | 0.012 | 0.157 | 0.188 |
Sheep s3 | 0.036 | 0.046 | 0.068 | 0.055 |
Sheep s4 | 0.020 | 0.024 | 0.097 | 0.086 |
Sheep s5 | 0.024 | 0.022 | 0.115 | 0.146 |
Mean | 0.022 | 0.026 | 0.130 | 0.138 |
SD | 0.009 | 0.013 | 0.057 | 0.067 |
Fe = distribution volume of the [18F]FDG-6-phosphate precursor pool, expressed as a fraction of lung volume; k3 = rate of phosphorylation of [18F]fluorodeoxyglucose ([18F]FDG) to [18F]FDG-6-phosphate by hexokinase. SD = standard deviation. The [18F]FDG net uptake rate is Ki = Fe · k3 (equation 3 in text). The increase of Ki in the smoke-exposed lung (fig. 3A) was associated with an increase of k3 in sheep s1 through s4, indicating increased phosphorylation of [18F]FDG by hexokinase. In sheep s5, the determinant of the Ki increase was an increase of Fe.