Voltage clamping single cells in intact Malpighian tubules of mosquitoes
Voltage clamping single cells in intact Malpighian tubules of mosquitoes
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DOI：
10.1152/ajprenal.2000.279.4.f747
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发表时间：
2000-10-01
影响因子：
4.2
通讯作者：
Beyenbach, KW
中科院分区：
文献类型：
--
作者：
Masia, R;Aneshansley, D;Beyenbach, KW
采用双电极电压钳（TEVC）方法对黄热病蚊马尔皮基管主细胞进行了研究。细胞内电压（V（pc））为-86.7 mV，输入电阻（R（pc））为388.5 k Ω（n = 49个细胞）。在6个细胞中，Ba（2+）（15 mM）对V（pc）的影响可以忽略不计，但它使R（pc）从325.3增加到684.5 k Ω（P < 0.001）。在Ba（2+）存在的情况下，白细胞激肽-VIII（1 μ M）使V（pc）增加到2101.8 mV（P < 0.001），使R（pc）减少到340.2 k Ω（P < 0.002）。电路分析得出以下结果：基底外侧膜电阻，652.0 k Ω;顶端膜电阻，340.2 k Ω;分流电阻（R（sh）），344.3 k Ω;跨细胞电阻，992.2 k Ω。顶膜的电阻分数（0.35）和跨细胞电阻与R（sh）的比值（3.53）与通过电缆分析在分离的灌注小管中获得的值密切一致，并证实TEVC方法在完整马氏管的单个主细胞中的有用性。二硝基苯酚（0.1 mM）使V（pc）从-94.3 mV可逆性去极化至-10.7 mV（P < 0.001），并使R（pc）从412 k Ω可逆性增加至2，879 k Ω（P < 0.001），氰化物（0.3 mM）的作用相同。代谢抑制对电压和电阻的显著影响表明ATP在产电和维持传导性运输途径中的作用。
Principal cells of the Malpighian tubule of the yellow fever mosquito were studied with the methods of two-electrode voltage clamp (TEVC). Intracellular voltage (V(pc)) was -86.7 mV, and input resistance (R(pc)) was 388.5 k Omega (n = 49 cells). In six cells, Ba(2+) (15 mM) had negligible effects on V(pc), but it increased R(pc) from 325.3 to 684.5 k Omega (P < 0.001). In the presence of Ba(2+), leucokinin-VIII (1 mu M) increased V(pc) to 2101.8 mV (P < 0.001) and reduced R(pc) to 340.2 k Omega (P < 0.002). Circuit analysis yields the following: basolateral membrane resistance, 652.0 k Omega; apical membrane resistance, 340.2 k Omega; shunt resistance (R(sh)), 344.3 k Omega; transcellular resistance, 992.2 k Omega. The fractional resistance of the apical membrane (0.35) and the ratio of transcellular resistance and R(sh) (3.53) agree closely with values obtained by cable analysis in isolated perfused tubules and confirm the usefulness of TEVC methods in single principal cells of the intact Malpighian tubule. Dinitrophenol (0.1 mM) reversibly depolarized V(pc) from -94.3 to -10.7 mV (P < 0.001) and reversibly increased R(pc) from 412 to 2,879 k Omega (P < 0.001), effects that were duplicated by cyanide (0.3 mM). Significant effects of metabolic inhibition on voltage and resistance suggest a role of ATP in electrogenesis and the maintenance of conductive transport pathways.