Hansen C P, Holstein-Rathlou N H, Frederiksen O
Pflugers Arch. 1986 May;406(5):497-501. doi: 10.1007/BF00583373.
The effects of the Ca2+-channel activator BAY K 8644 (a novel dihydropyridine) on transepithelial potential difference (Pd), electrical resistance (Rt), and unidirectional Na+-fluxes were studied in the rabbit gall-bladder. It was observed that BAY K 8644 at concentrations between 10(-7) and 10(-5) M induced regular oscillations in the transepithelial Pd, without affecting the mean value of Pd (or Rt). The mean oscillatory frequency was 18 mHz (approximately 1 cycle per min), and the mean amplitude was 30-35 microV. Oscillations were predominantly elicited from the serosal side. 10(-5) M BAY K 8644 reduced net Na+ -absorption by 16% by inhibiting the mucosa-to-serosa flux. Nifedipine blocked the Pd-oscillations but did not reverse the Na+-transport inhibition. The observed effects of BAY K 8644 are consistent with activation of Ca2+-channels and an increase in intracellular Ca2+-concentration.
在兔胆囊中研究了Ca2+通道激活剂BAY K 8644（一种新型二氢吡啶）对跨上皮电位差（Pd）、电阻（Rt）和单向Na+通量的影响。观察到，浓度在10(-7)至10(-5) M之间的BAY K 8644可诱导跨上皮Pd出现规则振荡，而不影响Pd（或Rt）的平均值。平均振荡频率为18 mHz（约每分钟1个周期），平均振幅为30 - 35 μV。振荡主要从浆膜侧引发。10(-5) M BAY K 8644通过抑制从黏膜到浆膜的通量使净Na+吸收减少了16%。硝苯地平阻断了Pd振荡，但未逆转Na+转运抑制。观察到的BAY K 8644的作用与Ca2+通道激活及细胞内Ca2+浓度增加一致。
