Table 2.
Maximum heart rate decrease (early phase) of wild-type and knockout mice in response to P2Y2/4 receptor activation
| Vehicle (%) | INS45973 (%) | ||||||
|---|---|---|---|---|---|---|---|
| 0.01 (mg kg−1) | 0.03 (mg kg−1) | 0.1 (mg kg−1) | 0.3 (mg kg−1) | 1 (mg kg−1) | 3 (mg kg−1) | ||
| WT | −1.1 ± 0.5 | 0.2 ± 0.3 | −0.5 ± 0.3 | −1.1 ± 0.7 | 2.0 ± 1.0 | −0.1 ± 0.6 | 1.2 ± 0.8 |
| P2Y2−/− | 0.9 ± 0.1 | 0.3 ± 0.1 | −1.2 ± 1.4 | 3.2 ± 0.8 | 7.7 ± 2.0 | 3.4 ± 0.9 | 6.1 ± 1.2 |
| eNOS−/− | 0.1 ± 0.5 | −0.1 ± 0.5 | −0.4 ± 1.9 | 0.2 ± 0.5 | 0.6 ± 0.3 | 1.2 ± 0.4 | 1.4 ± 0.4 |
| KCa3.1−/− | 0.8 ± 0.9 | 0.9 ± 0.4 | −1.2 ± 0.5 | 0.8 ± 0.3 | −0.3 ± 0.3 | 0.1 ± 0.6 | −0.8 ± 0.5 |
| KCa1.1−/− | 1.1 ± 0.5 | 0.7 ± 0.9 | 0.2 ± 0.1 | 0.6 ± 0.5 | 0.3 ± 0.6 | 0.4 ± 0.6 | 1.9 ± 1.2 |
| Cx37−/− | 1.9 ± 0.8 | 1.1 ± 0.6 | −0.3 ± 0.4 | 0.2 ± 0.5 | 0.1 ± 0.4 | 0.7 ± 0.4 | 1.2 ± 0.3 |
| Cx40−/− | −0.9 ± 0.6 | 0.4 ± 0.2 | −0.2 ± 0.7 | 0.9 ± 0.5 | 1.4 ± 1.3 | 0.4 ± 1.4 | 0.1 ± 1.1 |
Values are mean ± SEM. WT, wild-type mice; P2Y2−/−, P2Y2 receptor knockout mice, eNOS−/−, endothelial NO synthase knockout mice; Cx37−/−, connexin 37 knockout mice; Cx40−/−, connexin 40 knockout mice; KCa1.1−/−, big-conductance potassium channel knockout mice; KCa3.1−/−, intermediate-conductance potassium channel knockout mice. Additional analysis of previously published data (Rieg et al. 2011) from eNOS−/− and P2Y2−/− are included. n = 4–8 (two-way anova with repeated measures followed by Dunnett’s test).