Modulation of acetylcholine receptor channel by a polar component isolated from toxic Ostreopsis lenticularis extracts.
Methanol extracts obtained from O. lenticularis clones are toxic to mice and inhibit acetylcholine-induced contractions in frog skeletal muscle. Chromatographic fractionation of extracts produced two major fractions with different retention times. Single channel recordings in myocyte membrane patches exposed to more polar fraction showed the appearance of acetylcholine-activated channels whose mean current amplitude was nearly half that of the controls. Channel open times under control and experimental conditions were similar. Thus, this dinoflagellate fraction reduces the ionic conductance of nicotinic receptor channels without altering their lifetime.
Escalona De Motta
G
G
Institute of Neurobiology, University of Puerto Rico, San Juan 00901.
Mercado
J A
JA
Tosteson
T R
TR
González
I
I
Lasalde
J A
JA
D000818:Animals; D002478:Cells, Cultured; D002642:Chick Embryo; D002851:Chromatography, High Pressure Liquid; D004141:Dinoflagellida / Q000737:chemistry*; D004553:Electric Conductivity; D007473:Ion Channels / Q000502:physiology*; D008387:Marine Toxins / Q000302:isolation & purification / Q000494:pharmacology*; D000432:Methanol; D009132:Muscles / Q000196:embryology / Q000502:physiology; D011950:Receptors, Cholinergic / Q000502:physiology*
D007473:Ion Channels; D008387:Marine Toxins; D011950:Receptors, Cholinergic; D000432:Methanol