Inverse modulation of extracellular Na+- and K+-activities by ascorbate or methylene blue

On analyzing the mechanisms of the internal environment type redox regulation of physiological processes it was observed on frog rectus muscles that during acetylcholine contractures methylene blue pretreatment inhibited, but ascorbate pretreatment enhanced the slow transient changes of extracellular Na+-activity. At the same time, these modifications were inverse for K+-transients. Because k-strophantoside was capable of influencing these effects radically it seems highly plausible to assume that the principal site of action of these modulations is the inhibitory impact of methylene blue, while the enhancing effect of ascorbate on (Na+ + K+)-ATPase may likely be explained on redox basis.