頁籤選單縮合
題 名 | Characteristics of Store-Operated Ca[fec7]-Permeable Current in Monocytic U937 Cells |
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作 者 | Wu,Sheng-nan; Jan,Chung-ren; Li,Hui-fan; | 書刊名 | 中國生理學雜誌 |
卷 期 | 40:3 1997.09[民86.09] |
頁 次 | 頁115-120 |
分類號 | 361.1 |
關鍵詞 | Monocyte; Store-operated Ca[fec7]-permeable channel; Nifedipine; |
語 文 | 英文(English) |
英文摘要 | The electrophysiological properties of store-operated Ca��-permeable current in monocytic U937 cell line were characterized. The whole-cell voltage clamp technique with patch pipette containing Cs-internal solution was carried out. Membrane currents were elicited by the ramp pulses from -90mV to +40mV with a duration of 200 msec. After the presence of Ca �� -free Tyrode's solution plus cyclopiazonic acid(30 uM), A23187(10 uM)or ATP (30 uM)in cells for 10 minutes, a significant inward current was markedly elicited by further application of CaCl �� (2mM). This net inward current was reversed at about -12 mV with inward rectification The reversal potential of this current was not significantly altered by the replacement of intracellular Cl �� concentrations. The activation of this current is thus referred to as be store-operated Ca -permeable current (Isoc). The addition of LaCl �� (100 uM) or NiCl �� (100 uM) markedly blocked Isoc. The replacement of NaCl with N-methyl-D-glucamine chloride decreased the amplitude of this current at the level of -80mV by 50%. Nifedipine (3-100 uM) effectively suppressed the amplitude of Isoc in a concentration -dependent manner. The EC �t value for nifedipine-induced inhibition of Isoc is 10uM. However, verapamil (30 uM)or Bay K8644 (30 uM) did not produce any effect on it. The present studies indicate that in monocytic U937 cells, Ca �� entry elicited by store depletion is mediated through store-operated Ca �� -permeable channel which is responsive to nifedipine. |
本系統中英文摘要資訊取自各篇刊載內容。