Table 6. Effects of fructose and coformycin on the AICA riboside-induced decrease in oligomycin-sensitive JO2 and adenine nucleotide, ZMP and Pi concentrations in rat hepatocytes.
Hepatocytes isolated from 24 h-starved rats were incubated at 37°C in a Krebs/bicarbonate medium supplemented with 20 mM lactate, 2 mM pyruvate and 4 mM octanoate in the presence or absence of 5 mM fructose or 10 μM coformycin. After 15 min of preincubation, AICA riboside (1 mM final concentration) or its vehicle were added and cell samples were removed 30 min later for determination of the oligomycin-sensitive JO2, as described in the legend of Figure 2. Determination of adenine nucleotides, ZMP and Pi were performed in separate experiments. The results are expressed as means±S.E.M. (n=3). *P<0.05 compared with no AICA riboside addition; $P<0.05 compared with control incubated in the same conditions.
| (μmol·g dry hepatocytes−1) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| AICA riboside | ZMP μmol·g of dry hepatocytes−1 | JO2 μmol·min−1·g of dry hepatocytes−1 | ATP | ADP | AMP | ΣAN | Pi | ATP/ADP | |
| Control | − | < 0.1 | 17.8±0.4 | 10.4±0.4 | 0.9±0.1 | 3.5±0.3 | 15.1±0.5 | 12.6±0.1 | 13.2±1.6 |
| + | 21.2±1.1* | 8.7±0.6* | 8.4±0.5* | 1.7±0.1* | 2.5±0.2* | 12.2±0.7* | 4.4±0.1* | 5.1±0.4* | |
| Fructose | − | < 0.1 | 20.0±1.1$ | 7.4±0.4$ | 1.0±0.1 | 2.8±0.2$ | 11.3±0.6$ | 17.4±0.8$ | 8.7±1.3$ |
| + | 6.1±0.1*$ | 7.4±0.6*$ | 3.3±0.2*$ | 1.7±0.2* | 2.9±0.2 | 7.7±0.5*$ | 2.4±0.3*$ | 2.1±0.2*$ | |
| Coformycin | − | < 0.1 | 15.0±0.3$ | 12.3±0.2$ | 1.2±0.1$ | 4.3±0.2$ | 18.2±0.3$ | 11.3±0.3$ | 12.1±1.0 |
| + | 13.2±0.3*$ | 8.5±0.8* | 12.9±0.2$ | 3.0±0.1*$ | 3.7±0.4$ | 19.5±0.5$ | 4.3±0.3* | 4.7±0.2* | |