Akerman K E, Enkvist M O, Holopainen I
Abo Akademi, Department of Biochemistry and Pharmacy, Finland.
Neurosci Lett. 1988 Oct 17;92(3):265-9. doi: 10.1016/0304-3940(88)90600-3.
The membrane potential of astrocytes has been measured by monitoring the absorbance of a cyanine dye DiS-C2-(5). Ba2+, the phorbol ester 12-tetradecanoylphorbol myristateacetate (TPA) and the diglyceride, dioctanoylglycerol (DiC8) depolarize the membrane. Valinomycin which makes the membrane potential dependent on the K+ electrochemical potential evokes a hyperpolarization when added subsequently. The alpha-adrenergic receptor agonist phenylephrine was blocked by Ba2+, TPA, DiC8 and valinomycin. The results suggest that a protein kinase C-mediated reduction in the K+ permeability is responsible for the depolarizing effect of TPA, DiC8 and phenylephrine.
通过监测花青染料DiS-C2-(5)的吸光度来测量星形胶质细胞的膜电位。钡离子、佛波酯12-十四酰佛波醇乙酸酯（TPA）和二甘油酯二辛酰甘油（DiC8）可使膜去极化。缬氨霉素使膜电位依赖于钾离子电化学势，随后加入时会引起超极化。α-肾上腺素能受体激动剂去氧肾上腺素被钡离子、TPA、DiC8和缬氨霉素阻断。结果表明，蛋白激酶C介导的钾离子通透性降低是TPA、DiC8和去氧肾上腺素去极化作用的原因。
