Parameters of preischemic and postischemic recovery of contractile function in RGS6+/+ and RGS6−/− hearts
Data represent the mean ± S.E.M.
| Parameter | No. of Rats | Developed Pressure | +dP/dT | −dP/dT | EDP | Flow Rate |
|---|---|---|---|---|---|---|
| mmHg | mmHg/s | mmHg/s | mmHg | ml/min per g | ||
| Malea | ||||||
| Preischemic | ||||||
| RGS6+/+ | 10 | 107 ± 3 | 4107 ± 181 | −3328 ± 126 | 3 ± 1 | 30 ± 2 |
| RGS6−/− | 8 | 104 ± 3 | 3872 ± 89 | −3293 ± 72 | 4 ± 1 | 27 ± 1 |
| Recovery | ||||||
| RGS6+/+ | 10 | 42 ± 5* | 1670 ± 209* | −1289 ± 145* | 22 ± 2* | 19 ± 2* |
| RGS6−/− | 8 | 34 ± 3* | 1246 ± 109* | −1089 ± 109* | 24 ± 1* | 15 ± 1* |
| Femaleb | ||||||
| Preischemic | ||||||
| RGS6+/+ | 9 | 116 ± 4 | 4141 ± 218 | −3370 ± 135 | 3 ± 0.7 | 27 ± 2 |
| RGS6−/− | 9 | 121 ± 5 | 4118 ± 238 | −3454 ± 142 | 2 ± 0.5 | 27 ± 3 |
| Recovery | ||||||
| RGS6+/+ | 9 | 37 ± 3* | 1397 ± 137* | −1137 ± 86* | 8 ± 3 | 17 ± 2* |
| RGS6−/− | 9 | 34 ± 3* | 1178 ± 125* | −1017 ± 98* | 21 ± 5*,** | 15 ± 2* |
Preischemic contractile function was measured prior to the onset of ischemia. Postischemic recovery of contractile function was measured after 1 hour of reperfusion. Male and female data were analyzed separately by two-way analysis of variance with genotype (RGS6+/+ versus RGS6−/−) and time (preischemic versus postischemic recovery as a repeated measure) as factors. Bonferroni post hoc analysis was used to identify significant differences between specific groups.
↵a In male hearts, time (preischemic versus recovery) had significant effects on developed pressure [F = 375(1, 16), P < 0.0001], +dP/dT [F = 272(1, 16), P < 0.0001], −dP/dT [F = 354(1, 16), P < 0.0001], EDP [F = 209(1, 16), P < 0.001], and coronary flow rate [F = 148(1, 16), P = 0.04].
↵b In female hearts, time (preischemic versus postischemic recovery) had significant effects on developed pressure [F = 585(1, 16), P < 0.0001], +dP/dT [F = 402(1, 16), P < 0.0001], −dP/dT [F = 469(1, 16), P < 0.0001], EDP [F = 17(1, 16), P < 0.001], and coronary flow rate [F = 5(1, 16), P = 0.04].
↵* P < 0.001 (significant difference compared with preischemic value); **P < 0.05 (significant difference compared with the recovery of EDP in RGS6+/+ hearts).