Modulation by Mibefradil of the Histamine-Induced Ca2+ Entry in Human Aortic Endothelial Cells
| Autor: | Kazuto Yazawa, Kyoichi Ono, Toshihiko Iijima |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Patch-Clamp Techniques
Time Factors Fura-2 Voltage clamp Pharmacology Histamine Agonists chemistry.chemical_compound Chloride Channels medicine Humans Patch clamp Aorta Cells Cultured Mibefradil Antagonist Depolarization Calcium Channel Blockers chemistry Calcium Endothelium Vascular Histamine Intracellular medicine.drug |
| Zdroj: | Japanese Journal of Pharmacology. 90:125-130 |
| ISSN: | 0021-5198 |
| Popis: | The effect of mibefradil, known as a T- and L-type Ca(2+) channel antagonist, on the histamine-induced Cl(-) current and Ca(2+) entry was investigated in human aortic endothelial cells by the fluorescence measurement of intracellular Ca(2+) concentration ([Ca(2+)](i)) combined with the patch clamp method. Mibefradil (10 micro M) inhibited both the Cl(-) current and Ca(2+) entry in a concentration-dependent manner with an IC(50) value of 4.8 and 2.6 micro M for the Cl(-) current and [Ca(2+)](i), respectively. These values were comparable to those reported for the inhibition of the T-type Ca(2+) channel and other Cl(-) channels. The suppression of Ca(2+) entry is not caused by the inhibition of the Cl(-) current and the resulting depolarization since the inhibition was still observed under the voltage clamp condition. These results suggest that mibefradil is a potent blocker not only for the agonist-induced Cl(-) current but also Ca(2+) entry channels in vascular endothelial cells. |
| Databáze: | OpenAIRE |
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