FIGURE 2.
Thymidine-phosphorylating activity of Dm-dNK mice. A, enzyme activity determined as [3H]dThd phosphorylation (pmol of dTMP/mg of protein) in extracts of brain, heart, liver, skeletal muscle, and kidney of wt and Dm-dNK+/− mice that were 1-month-old (blue filled diamond, wt 1; green filled triangle, wt 2; red filled square, Dm-dNK+/− 1; purple filled circle, Dm-dNK+/− 2). The enzyme activity was measured over a time period of 30 min. The enzyme activity was higher in the Dm-dNK+/− mice when compared with the wt mice in all the tissues studied, and this increase was statistically significant for all the tissues (p < 0.0001). Data represent average of the three time points at which activity was measured (10, 20, and 30 min). B, estimated activity of Dm-dNK determined as [3H]dThd phosphorylation (pmol of dTMP/mg/min) in extracts of skeletal muscle samples of 1-month-old (n = 2 wt, n = 2 Dm-dNK+/−), 3-month-old (n = 3 wt, n = 2 Dm-dNK+/−), and 6-month-old (n = 3 wt, n = 3 Dm-dNK+/−) mice. No significant difference in enzymatic activity was observed in Dm-dNK+/− samples in 1-, 3-, and 6-month-old mice (p > 0.05). C, difference in enzyme activity determined as phosphorylation of [3H]BVDU (pmol of BVDUMP/mg/min) in kidney of 1-month-old wt (n = 3), Dm-dNK+/− (n = 2), and Dm-dNK+/+ (n = 1) mice.