Cardiac-directed expression of adenylyl cyclase and heart rate regulation.

摘要: Mice with cardiac-directed overexpression of AC(VI) show increased cardiac responsiveness to beta-adrenergic receptor stimulation but regulation heart rate is unknown. Telemetry was used test the hypothesis that mice overexpressing adenylyl cyclase type VI (AC(VI)) would have normal regulation. were generated using alphaMHC promoter and studied 10 days after implantation telemetry devices. Cardiac transgene presence expression verified PCR, RT-PCR immunoblotting. Ambulatory rates assessed time frequency domain analysis over two 24 hour light-dark cycles. Heart then following pharmacological blockade. Time analyses showed ambulatory unchanged (AC(VI): 597 +/- 15 (SEM) bpm, Control: 595 12 bpm; p = 0.92). Circadian variability preserved not different from control (ANOVA, 0.52). Frequency also unchanged. No difference in response autonomic blockade found (intrinsic rate: 622 17 616 16 0.79). In conclusion, conscious variability. Overexpression does result altered contrast other elements signaling pathway.