High-K+ depolarization induced decrease in cytoplasmic pH in nerve fibersстатья
Информация о цитировании статьи получена из
Web of Science
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 27 мая 2015 г.
Аннотация:Cytoplasmic pH (pH(i)) in frog nerve fibers (sciatic nerve and its thin bundles) was measured using fluorescein diacetate. Membrane depolarization was caused by partial or complete isoosmotic replacement of Na+ by K+ in the external solution. In all experiments, high-K+ solution induced a concentration-dependent decrease in pH(i) which could be reversibly enhanced by repetitive (50 Hz) stimulation of the nerve fibres. The removal of Ca2+ from the external medium or addition Co2+ and Ni2+ (1 mM), Ca2+-channel blockers as well as Zn2+ (100 mu M), a blocker of voltage-sensitive H+-channels, to the high-K+-solution did not attanuate the pH(i) decrease. The blockade of K+-channels by 10 mM TEA also failed to decrease the effect of K+-depolarization on pH(i). The mixture of 5 mu M TTX and 0.05 mM procaine effeciently prevented the K+-induced decrease in pH(i). The results obtained suggested that the decrease in pH(i) caused by a long-term membrane depolarization was mainly due to the increase in H+-influx through noninactivating Na+-channels.