Chinese natural compound decreases pacemaking of rabbit cardiac sinoatrial cells by targeting second messenger regulation of f-channels
- Department of Biosciences, The Cell Physiology Lab and “Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata”, Università degli Studi di Milano, Italy
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Tianjin Medical University, China
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, China
- College of Pharmaceutical Sciences, Zhejiang University, China
- Institute of Traditional Chinese Medicine Tianjin University of Traditional Chinese Medicine, China
Figures
Figure 1
Tongmai Yangxin (TMYX) reduces the spontaneous rate of rabbit sinoatrial node (SAN) myocytes.
(A) Representative time-courses (top) and sample traces (bottom) of spontaneous action potentials (APs) recorded from rabbit SAN cells in control conditions and in the presence of TMYX (2 and 6 …
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Figure 1—source data 1
Quantification and statistics of TMYX effect on spontaneous activity (APs) recorded from single sinoatrial node cells.
- https://cdn.elifesciences.org/articles/75119/elife-75119-fig1-data1-v1.xlsx
Figure 2 with 2 supplements
Dual action of Tongmai Yangxin (TMYX) on the voltage dependence and maximal conductance of the If current.
(A) Representative whole-cell currents elicited by a double-step protocol (–65 mV/1.5 s and –125 mV/0.5 s; holding potential –35 mV) before (control) and during drug (TMYX 6 mg/ml) perfusion. (B) …
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Figure 2—source data 1
Quantification and statistics of TMYX (6 mg/ml) effect on the voltage-dependence and fully-activated I/V properties of the funny current.
- https://cdn.elifesciences.org/articles/75119/elife-75119-fig2-data1-v1.xlsx
Figure 2—figure supplement 1
Dual action of Tongmai Yangxin (TMYX) (2 mg/ml) on the voltage dependence and maximal conductance of the If current.
(A) Representative whole-cell currents (bottom) elicited by a double-step protocol (top, –65 mV/1.5 s and –125 mV/0.5 s from a holding potential of –35 mV) in control condition and during TMYX (2 …
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Figure 2—figure supplement 1—source data 1
Quantification and statistics of TMYX (2 mg/ml) effect on the voltage-dependence and fully-activated I/V properties of the funny current.
- https://cdn.elifesciences.org/articles/75119/elife-75119-fig2-figsupp1-data1-v1.xlsx
Figure 2—figure supplement 2
Effects of Tongmai Yangxin (TMYX) (6 mg/ml) on the voltage dependence of the steady-state If current measured at different voltages.
Left: Mean ± SEM steady-state current/voltage relation obtained from n = 7 cells in control (filled circles) and during TMYX perfusion (empty circles). Currents were elicited by a train of eight …
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Figure 2—figure supplement 2—source data 1
Quantification of TMYX (6 mg/ml) effect on the voltage-dependence of the steady-state funny current.
- https://cdn.elifesciences.org/articles/75119/elife-75119-fig2-figsupp2-data1-v1.xlsx
Figure 3 with 2 supplements
Tongmai Yangxin (TMYX) action does not involve muscarinic receptor activation.
(A) Representative sample current traces recorded during steps to –65 mV in the presence and in the absence of TMYX (6 mg/ml, top) and acetylcholine (ACh) (1 µM, bottom) delivered alone (left) or in …
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Figure 3—source data 1
Quantification and statistics of TMYX (6 mg/ml) effect on rate and on the funny current amplitude in the presence and in the absence of muscarinic block.
- https://cdn.elifesciences.org/articles/75119/elife-75119-fig3-data1-v1.xlsx
Figure 3—figure supplement 1
The action of Tongmai Yangxin (TMYX) is not mediated by the activation of the adenosine receptor.
(A) Representative steady-state time-courses (top) and sample current traces (bottom) recorded at –65 mV for 2.75 s (holding potential, –35 mV) in control condition and in the presence of TMYX (6 …
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Figure 3—figure supplement 1—source data 1
Quantification and statistics of TMYX (6 mg/ml) effect on the funny current in the presence and in the absence of the adenosine receptor block.
- https://cdn.elifesciences.org/articles/75119/elife-75119-fig3-figsupp1-data1-v1.xlsx
Figure 3—figure supplement 2
The action of Tongmai Yangxin (TMYX) is not mediated by PKA activation.
(A) Representative sample traces of spontaneous action potentials (APs) showing the effect of TMYX (2 mg/ml) in control condition (left) and in the presence of the PKA blocker H-89 (1 µM, right). (B)…
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Figure 3—figure supplement 2—source data 1
Quantification and statistics of TMYX (2 mg/ml) effect on APs in the presence of the PKA blocker H-89.
- https://cdn.elifesciences.org/articles/75119/elife-75119-fig3-figsupp2-data1-v1.xlsx
Figure 4 with 1 supplement
The Tongmai Yangxin (TMYX)-induced reduction of the whole-cell If is counteracted by increasing concentrations of intracellular cAMP.
(A) Representative time-courses (left) of the steady-state amplitudes of the current recorded at –65 mV/2.75 s (sample traces, right) in control conditions and in the presence of TMYX (6 mg/ml). …
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Figure 4—source data 1
Quantification and statistics of TMYX (6 mg/ml) effects on the funny current in the presence of different cAMP concentrations.
- https://cdn.elifesciences.org/articles/75119/elife-75119-fig4-data1-v1.xlsx
Figure 4—figure supplement 1
Increasing concentrations of intracellular cAMP reduce the If inhibitory action of Tongmai Yangxin (TMYX).
(A) The bar-graph illustrates the effects of TMYX (6 mg/ml) on the whole-cell If current (elicited at –65 mV) assessed in basal condition, in the presence of the phosphodiesterase inhibitor …
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Figure 4—figure supplement 1—source data 1
Quantification and statistics of TMYX (2 mg/ml) effects on the funny current in the presence of increasing cAMP concentrations.
- https://cdn.elifesciences.org/articles/75119/elife-75119-fig4-figsupp1-data1-v1.xlsx
Figure 5 with 1 supplement
Tongmai Yangxin (TMYX) reduces the If current by antagonizing its cAMP-induced modulation.
(A) Sample time-courses (left) and current traces (right) of If amplitudes recorded in inside-out macropatches during hyperpolarizing steps (–105 mV); cAMP (1, 10, 100 µM, n = 4–6) was perfused …
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Figure 5—source data 1
Quantification of the TMYX (6 mg/ml) ability to antagonize the cAMP-induced (dose-response) modulation of the funny current.
- https://cdn.elifesciences.org/articles/75119/elife-75119-fig5-data1-v1.xlsx
Figure 5—figure supplement 1
Tongmai Yangxin (TMYX) does not directly influence the intrinsic properties of f-channels.
(A) Representative If current traces recorded from an inside-out macropatch at a voltage of –105 mV (holding potential, –35 mV) in control condition and in the presence of TMYX (6 mg/ml). The same …
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Figure 5—figure supplement 1—source data 1
Quantification and statistics of TMYX (6 mg/ml) effects on the intrinsic voltage dependence and maximal conductance of the funny current.
- https://cdn.elifesciences.org/articles/75119/elife-75119-fig5-figsupp1-data1-v1.xlsx
Tables
Key resources table
| Reagent type (species) or resource | Designation | Source or reference | Identifiers | Additional information |
|---|---|---|---|---|
| Strain, strain background (Oryctolagus cuniculus) | New Zealand rabbit | Charles River | Female, 35–41 days | |
| Chemical compound, drug | Acetylcholine chloride (ACh) | Sigma-Aldrich (Merck) | A6625 | |
| Chemical compound, drug | Adenosine 3′,5′-cyclic monophosphate sodium salt monohydrate (cAMP) | Sigma-Aldrich (Merck) | A6885 | |
| Chemical compound, drug | Forskolin | Sigma-Aldrich (Merck) | F6886 | |
| Chemical compound, drug | 1,3-Dipropyl-8-cyclopentylxanthine (DPCPX) | Sigma-Aldrich (Merck) | C101 | |
| Chemical compound, drug | 3-Isobutyl-1-methylxanthine (IBMX) | Sigma-Aldrich (Merck) | I5879 | |
| Chemical compound, drug | H-89 dihydrochloride hydrate (H-89) | Sigma-Aldrich (Merck) | B1427 | |
| Software, algorithm | pClamp – Clampfit | Molecular Devices | RRID:SCR_011323 | |
| Software, algorithm | pClamp – Clampex | Molecular Devices | RRID:SCR_011323 | Version 10.7 |
| Software, algorithm | Origin | Origin Lab | RRID:SCR_014212 | OriginPro 2020 |
| Software, algorithm | Prism | GraphPad Software | RRID:SCR_002798 | Version 5 |
| Other | Tongmai Yangxin | Le Ren Tang Pharmaceutical Factory |
