The Ca(++)-channel blocker Ro 40-5967 blocks differently T-type and L-type Ca++ channels
The effects of Ro 40-5967, a nondihydropyridine Ca++ channel blocker, on low-voltage activated (T-type) and high-voltage activated (L-type) Ca++ channels were compared. L-type barium currents were measured in Chinese hamster ovary cells stably transfected with the alpha 1 subunit of the class Cb Ca+...
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| Autores principales: | , , , |
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| Formato: | Article (Journal) |
| Lenguaje: | inglés |
| Publicado: |
December 1994
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| In: |
The journal of pharmacology and experimental therapeutics
Year: 1994, Volumen: 271, Número: 3, Pages: 1483-1488 |
| ISSN: | 1521-0103 |
| DOI: | 10.1016/S0022-3565(25)24034-4 |
| Acceso en línea: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1016/S0022-3565(25)24034-4 Verlag, lizenzpflichtig, Volltext: https://www.sciencedirect.com/science/article/pii/S0022356525240344 
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| Notas de Autor: | G. Mehrke, X.G Zong, V. Flockerzi, F. Hofmann |
| Sumario: | The effects of Ro 40-5967, a nondihydropyridine Ca++ channel blocker, on low-voltage activated (T-type) and high-voltage activated (L-type) Ca++ channels were compared. L-type barium currents were measured in Chinese hamster ovary cells stably transfected with the alpha 1 subunit of the class Cb Ca++ channel. T-type barium currents were investigated in human medullary thyroid carcinoma cells. The Ba++ currents of human medullary thyroid carcinoma cells were transient, activated at a threshold potential of -50 mV with the maximum at -14 +/- 3.2 mV and blocked by micromolar Ni++. The T- and L-type current inactivated with time constants of 33.4 +/- 4.1 and 416 +/- 26 msec at maximum barium currents, respectively. Ro 40-5967 inhibited reversibly the T- and L-type currents with IC50 values of 2.7 and 18.6 microM, respectively. The inhibition of the L-type current was voltage-dependent, whereas that of the T-type current was not. Ro 40-5967 blocked T-type current already at a holding potential of -100 mV. The different types of block, i.e., voltage-dependent vs. tonic block, may contribute to the pharmacological profile of Ro 40-5967 in intact animals. |
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| Notas: | Elektronische Reproduktion der Druck-Ausgabe 31. Januar 2025 Gesehen am 17.02.2025 |
| Descripción Física: | Online Resource |
| ISSN: | 1521-0103 |
| DOI: | 10.1016/S0022-3565(25)24034-4 |