Kuroki M, Kamo N, Kobatake Y, Okimasu E, Utsumi K
Biochim Biophys Acta. 1982 Dec 22;693(2):326-34. doi: 10.1016/0005-2736(82)90439-4.
The membrane potential of guinea pig polymorphonuclear leukocytes has been assessed with two indirect probes, tetraphenylphosphonium (TPP+) and 3,3'-dipropylthiadicarbocyanine (disS-C3-(5)). The change in TPP+ concentration in the medium was measured with a TPP+-selective electrode. By monitoring differences in accumulation of TPP+ in media containing low and high potassium concentrations, a resting potential of -58.3 mV was calculated. This potential is composed of a diffusion potential due to the gradient of potassium, established by the Na+, K+ pump, and an electrogenic potential. The chemotactic peptide fMet-Leu-Phe elicits a rapid efflux of accumulated TPP+ (indicative of depolarization) followed by its reaccumulation (indicative of repolarization). In contrast, stimulation with concanavalin A results in a rapid and sustained depolarization without a subsequent repolarization. The results obtained with TPP+ and diS-C3-(5) were comparable. Such changes in membrane potential were observed in the absence of extracellular sodium, indicating that an inward movement of sodium is not responsible for the depolarization. Increasing potassium levels, which lead to membrane depolarization, had no effect on the oxidative metabolism in nonstimulated or in fMet-Leu-Phe-stimulated cells. Therefore, it seems unlikely that membrane depolarization per se is the immediate stimulus for the respiratory burst.
已使用两种间接探针——四苯基鏻（TPP⁺）和3,3'-二丙基硫代二碳菁（disS-C3-(5)）评估了豚鼠多形核白细胞的膜电位。用TPP⁺选择性电极测量培养基中TPP⁺浓度的变化。通过监测在低钾和高钾浓度培养基中TPP⁺积累的差异，计算出静息电位为-58.3 mV。该电位由钠钾泵建立的钾离子梯度产生的扩散电位和一个生电电位组成。趋化肽fMet-Leu-Phe引发积累的TPP⁺快速外流（表明去极化），随后是其重新积累（表明复极化）。相反，用伴刀豆球蛋白A刺激会导致快速且持续的去极化，且随后没有复极化。用TPP⁺和diS-C3-(5)获得的结果具有可比性。在没有细胞外钠的情况下观察到了这种膜电位变化，这表明钠的内流不是去极化的原因。增加钾水平会导致膜去极化，但对未刺激或fMet-Leu-Phe刺激的细胞的氧化代谢没有影响。因此，膜去极化本身似乎不太可能是呼吸爆发的直接刺激因素。
