Table 1.
Effects of 14 days of cold exposure on isoform-specific AMPK activity
| Wild-type |
α1-AMPK−/− |
|||
|---|---|---|---|---|
| Control | Cold | Control | Cold | |
| BAT | ||||
| α1-AMPK* | 83.6 ± 13.8 | 133.5 ± 14.7 | −0.1 ± 0.1 | 0.0 ± 0.1 |
| α2-AMPK‡ | 9.7 ± 1.7 | 10.5 ± 1.1 | 14.2 ± 1.8 | 14.1 ± 2.3 |
| WAT | ||||
| α1-AMPK* | 62.3 ± 15.4 | 109.1 ± 12.9 | 0.1 ± 0.4 | 0.4 ± 0.3 |
| α2-AMPK†‡ | 3.3 ± 0.7 | 6.5 ± 0.9 | 5.5 ± 1.5 | 10.8 ± 1.5 |
| Liver | ||||
| α1-AMPK | 21.3 ± 3.6 | 28.0 ± 1.4 | −0.2 ± 0.1 | 0.0 ± 0.1 |
| α2-AMPK‡ | 11.2 ± 2.5 | 12.8 ± 1.7 | 22.0 ± 2.7 | 16.7 ± 2.1 |
| Skeletal muscle | ||||
| α1-AMPK | 5.4 ± 1.4 | 5.0 ± 1.0 | 0.0 ± 0.1 | 0.0 ± 0.1 |
| α2-AMPK‡ | 3.2 ± 0.3 | 4.5 ± 0.3 | 2.8 ± 0.3 | 5.0 ± 0.9 |
Values (means ± SE) are expressed in pmol 32P·min−1·mg protein−1 (n = 6/group). AMPK, AMP-activated protein kinase; BAT, brown adipose tissue; WAT, white adipose tissue.
*
Significant effect of temperature on α1-AMPK activity (t-test).
†
Significant effect of temperature on α2-AMPK activity (2-way ANOVA).
‡
Significant effect of genotype on α2-AMPK activity (2-way ANOVA).