Fig. 2.
Measurement of LTCCI (A) and heart rate (HR; B) in WT mice obtained at Bsl, dobutamine (Dob), dobutamine + carbacholamine (Dob + CCh), ATL313, and nifedipine. Dob-induced increases in LTCCI and HR were reversed with Dob + CCh. With adenosine A2a receptor stimulation using ATL313, LTCCI decreased, whereas HR increased, reflecting a negative LTCCI-frequency response. Nifedipine, an LTCC inhibitor, decreased LTCCI significantly while not having any effect on HR. *P < 0.05 vs. Bsl; †P < 0.05 vs. Dob. BPM, beats/min; HB, heartbeat.