We previously demonstrated a role for voltage-dependent K(+) (K(V)) channels in coronary vasodilation elicited by myocardial metabolism and exogenous H(2)O(2), as responses were attenuated by the K(V) channel blocker 4-aminopyridine (4-AP). Here we tested the hypothesis that K(V) channels participate in coronary reactive hyperemia and examined the role of K(V) channels in responses to nitric ox...

Traumatic peripheral nerve damage is a major medical problem without effective treatment options. In repurposing studies on 4-aminopyridine (4-AP), a potassium channel blocker that provides symptomatic relief in some chronic neurological afflictions, we discovered this agent offers significant promise as a small molecule regenerative agent for acute traumatic nerve injury. We found, in a mouse ...

K(+) channel blockers such as 4-aminopyridine (4-AP) can be toxic to neurons; the cellular mechanism underlying the toxicity, however, is obscure. In cultured mouse cortical neurons, we tested the hypothesis that the toxic effect of 4-AP might result from inhibiting the Na(+),K(+)-ATPase (Na(+),K(+)-pump) and thereafter induction of a hybrid death of concomitant apoptosis and necrosis. The Na(+...

BACKGROUND Hypoxic pulmonary vasoconstriction (HPV) is impaired during inflammatory lung processes such as pneumonia or the acute respiratory distress syndrome. Voltage-gated potassium channels play a central role in mediating HPV. The aim of this study was to determine whether 4-aminopyridine (4-AP), a known voltage-gated potassium channel inhibitor, may restore HPV in sepsis. METHODS The ef...

Background. 4-Aminopyridine (4-AP) is a drug that is used to improve motor fatigue in patients suffering from multiple sclerosis (MS). Medication error can occur, as commercial preparation may not be available in some countries. Case Presentation. A 58-year-old woman with progressive MS presented with status epilepticus. She was receiving 4-AP for more than 3 years. The symptoms started soon af...

4-Aminopyridine (4-AP) is a well known convulsant that enhances the release of both excitatory and inhibitory neurotransmitters in the CNS. Low concentrations of 4-AP (approximately 100 microM) readily induce synchronized discharges in the hippocampus that are blocked by tetrodotoxin (TTX), suggesting that they require Na(+)-dependent action potentials in addition to the enhanced release of neu...

To study the potential role of potassium channels in the taste response to potassium salts, we applied 4-aminopyridine (4-AP) to the anterior rat tongue and recorded chorda tympani nerve taste responses to chemical stimuli. 4-aminopyridine is a pharmacological blocker that reduces potassium conductance through potassium channels in nerve and muscle. Summated neural responses to stimuli dissolve...

introduction: human embryonic stem cells (hescs) are pluripotent cells that can proliferate and differentiate to many cell types. their electrophysiological properties have not yet been chracterzed. in this study, the passive properties (such as resting membrane potential, input resistance and capacitance) and the contribution of delayed rectifier k+ channel currents to the membrane conductance...

Spinal cord astrocytes express four biophysically and pharmacologically distinct voltage-activated potassium (K(+)) channel types. The K(+) channel blocker 4-aminopyridine (4-AP) exhibited differential and concentration-dependent block of all of these currents. Specifically, 100 microM 4-AP selectively inhibited a slowly inactivating outward current (K(SI)) that was insensitive to dendrototoxin...