4-Aminopyridine on the spontaneous contractions of isolated intestine
Gónzalez, D.; Morales-Aguilera, A.
Archivos de Investigacion Medica 20(3): 247-253
1989
ISSN/ISBN: 0066-6769 PMID: 2561257 Document Number: 340855
The effects of 4-aminopyridine on isolated spontaneously active segments of rabbit jejunum were studied. The drug produced a dose-dependent increase of the tonic and phasic components of the contractile activity with an ED50 of 2 x 10(-5) M, lower than the reported dose for striated muscle. No effects were observed on the frequency of contractions at the concentrations of 4-aminopyridine used in this study. The results suggest both, an effect on the jejunal innervation and a direct action of the drug on the intestinal smooth muscle. The former mechanism includes the release of acetylcholine and is partially blocked by atropine. Direct effects of 4-aminopyridine on intestinal smooth muscle cells can be present at relatively low doses and they must be carefully evaluated during the suggested therapy of several human diseases with 4-aminopyridine.