The Ca2+-activated monovalent cation selective transient receptor potential melastatin 4 (TRPM4) channel expressed in pancreatic β-cells is implicated in the β-cell function and insulin secretion, but how pharmacological function of TRPM4 channel affects membrane excitability of β-cells remains largely unknown. Here, we report that pharmacological inhibition of TRPM4 by specific inhibitor 9-phenanthrol attenuates electrical activities of pancreatic β-cells. In whole-cell current clamp recordings, 9-phenanthrol results in inhibition of action potential frequency induced by tolbutamide of the INS-1 pancreatic β-cells in a dose-dependent manner with an IC50 value of 14.99 ± 7.93 μmol·L-1. Similarly, 9-phenanthrol also inhibited action potential firing in INS-1 cells stimulated by current injection. Further recordings of β-cells demonstrate the significant inhibitory effects on action potential peak and action potential amplitude by 9-phenanthrol. Taken together, our results show the involvement of TRPM4 channel function in pancreatic β-cells depolarization and action potential, it provides pharmacological experimental methods and theoretical support for the study of TRPM4 channel in pancreatic β-cells.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |