Table 1 Kinetic parameters of adenosine transport mediated by ENT1 and ENT2 in rat podocytes.

From: Deficient Insulin-mediated Upregulation of the Equilibrative Nucleoside Transporter 2 Contributes to Chronically Increased Adenosine in Diabetic Glomerulopathy

 

Vmax (pmol/µg protein/sec)

Km (µM)

Vmax/Km

ENT1

5 mM D-Glucose

2.955 ± 0.1870

65.05 ± 13.73

0.045

25 mM D-Glucose

1.333 ± 0.0829a

66.74 ± 13.71

0.020a

5mM D-Glucose + insulin

3.678 ± 0.2044b

64.31 ± 11.98

0.057

25mM D-Glucose + insulin

1.279 ± 0. 0930a

73.77 ± 17.03

0.017a

ENT2

5mM D-Glucose

3.544 ± 0.3037

119.6 ± 27.10

0.030

25mM D-Glucose

1.913 ± 0.1828a

137.1 ± 32.98

0.014a

5mM D-Glucose + insulin

5.170 ± 0.3442b

128.1 ± 22.00

0.040

25mM D-Glucose + insulin

3.576 ± 0.2321c

144.1 ± 23.11

0.025c

  1. Primary cultured podocytes were exposed to 5mM or 25mM D-glucose for 24 h and supplemented with 10nM insulin the last 30 minutes.
  2. Adenosine transport was assayed at 0–500 µM adenosine, 60 seconds to 22 °C. Graphics depicting adenosine uptake mediated ENT1 and ENT2 are in Fig. 1 of supplementary material.
  3. Data represent means ± S.D. aP < 0.05 versus 5 mM D-Glucose. bP < 0.05 versus 5mM D-Glucose. cP < 0.05 versus 25 mM D-Glucose. n = 9 independent experiments each one in duplicates.
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