Ion channels of Fasciola hepatica incorporated into planar lipid bilayers.
Ion channels are important target sites of anthelmintics, but little is known about those in Fasciola hepatica. In this work, we applied a planar lipid bilayer technique to characterize the properties of single ion channels in F. hepatica. Under a 200/40 mM KCl gradient, a large conductance channel of 251 pS was observed in 18% of the membranes studied. The channel was selective to K(+) over Cl(-) with a permeability ratio of K(+) to Cl(-) (PK/PCl) of 4.9. Open state probability (Po) of the channel was less than 0.5 and dependent on voltage (-60 to approximately +40 mV) and Ca(2+) (approximately 100 microM). The other two types of single channels observed in 11 and 5% of membranes, respectively, were a K(+)-permeable channel of 80 pS (PK/PCl=4.6) and a Cl(-)-permeable channel of 64 pS (PK/PCl=0.058). Open state probability of both channels showed little voltage dependence. The results indicate that distinct single channels of 60 to approximately 251 pS are present in relative abundance and, in addition, that the planar lipid bilayer technique can be a useful tool for the study of single ion channels in F. hepatica.
Laboratory of Pharmacology, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University, San 56-1 Sillim-dong, Kwanak-gu, Seoul 151-742, Republic of Korea.
J H
JH
Jang
S D
SD
Kim
J B
JB
Park
S J
SJ
Hong
P D
PD
Ryu
D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D018118:Chloride Channels / Q000502:physiology; D005210:Fasciola hepatica / Q000502:physiology*; D066298:In Vitro Techniques; D008051:Lipid Bilayers / Q000737:chemistry*; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000737:chemistry* / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley
D018118:Chloride Channels; D008051:Lipid Bilayers; D015221:Potassium Channels