Possible Interaction: 4-Aminopyridine and Adenosine

“Simultaneous recordings of brain activity, extracellular ADO and pH shifts demonstrated that ADO decreases at the onset and progressively rises toward the end of SLEs induced by either BMI or 4-aminopyridine (4AP; 50 μM), reaching maximal values 1-5 min after SLE termination.”

“ 4-Aminopyridine , a blocker of potassium channels at 10mM, prevented the cardiac arrest produced by adenosine and ATP, while BayK 8644, activator of calcium channels, did not prevent cardiac arrest.”

“When 4-AP and antagonists of adenosine action were combined, a partial recovery of synaptic transmission was consistently seen during the course of repetitive stimulation.”

“Both 4-aminopyridine (20 μM) and high frequencies of stimulation (3, 10 and 20 Hz) were effective in nearly completely abolishing the inhibitory effect of adenosine on ganglionic transmission.”

“ 4-AP and Ca2+ significantly antagonized the inhibitory actions of adenosine on cardiac processes, more strongly on contractility and with 4-AP more potent than Ca2+.”

“ Adenosine inhibits synaptosomal exocytosis of glutamate, triggered by KCl or by the K(+) channel inhibitor, 4-aminopyridine (4-AP), without affecting Ca(2+) influx.”

“These results suggest that adenosine may activate 4-AP or ATP-sensitive potassium channels via an A1-receptor-mediated mechanism and consequently inhibit anoxia-induced [Ca2+]i elevation in hippocampal neurons.”

“This effect of adenosine could be suppressed by adenosine A1 receptor antagonist CPT or potassium channel blockers, 4-AP and glipizide.”

“By contrast, we have previously shown that adenosine enhances A-current, thereby reducing action potential duration in locus ceruleus neurons, and these effects are blocked by 4-aminopyridine but not barium.”

“The peak inhibition of tension by adenosine (112 μM) (60.0%) was also significantly reduced to 37.4% in the presence of 4-AP (10 mM).”