糖尿病性ニューロパチーにおける軸索イオンチャンネル機能

Diabetic neuropathy is characterized by the early decrease in motor conduction velocities and loss of vibratory sense. Autonomic dysfuncion may also be present in the early stage. These clinical features are not explainted by demyelination or Wallerian degeneration. Threshold tracking techniques such as latent addition or threshold electrotonus have been developed to explore the function of the ion channels non-invasively. Decreased peak Na current was found in diabetic patients, and is correlated with the decreased in motor conduction velocities. In ward rectifiers, which counteract membrane hyperpolatization, were found deficient in diabetic patients and models. This may lead to frequency-dependent conduction block, thus accounting for the early loss of vibratory sense. These clinical tests of axonal function is expected to reveal physiological information which the conventional nerve conduction studies could not provide previously.