Ion channel activity from the midgut brush-border membrane of gypsy moth (Lymantria dispar) larvae
Peyronnet, O; Vachon, V; Schwartz, JL; Laprade, R
| HERO ID | 647923 |
|---|---|
| In Press | No |
| Year | 2000 |
| Title | Ion channel activity from the midgut brush-border membrane of gypsy moth (Lymantria dispar) larvae |
| Authors | Peyronnet, O; Vachon, V; Schwartz, JL; Laprade, R |
| Journal | Journal of Experimental Biology |
| Volume | 203 Pt 12 |
| Issue | 12 |
| Page Numbers | 1835-1844 |
| Abstract | Ion channels from the midgut apical membrane of gypsy moth (Lymantria dispar) larvae were studied following mechanical fusion of brush-border membrane vesicles with planar phospholipid bilayer membranes. In symmetrical 300 mmol l(-)(1) KCl (pH 9.0), nine different channels with conductances ranging from 27 to 795 pS and linear current/voltage relationships were resolved. In the presence of a KCl gradient across the bilayer (450 mmol l(-)(1 )cis/150 mmol l(-)(1 )trans), 11 different conductance levels ranging from 16 to 850 pS were detected. The channels were slightly cationic: the zero-current reversal potential was shifted by -5 mV to -21 mV compared with symmetrical KCl conditions, corresponding to p(K)/p(Cl) permeability ratios of 1.5-8.0. Most channels were neither voltage-dependent nor Ca(2+)-sensitive and displayed complex gating kinetics. Addition of Ba(2+) or Cs(+) to both sides of the bilayer had little effect on channel activity, but fewer distinct channels were observed when KCl was replaced by potassium gluconate, suggesting an effect of Cl(-) on channel activity. A reduced number of channels was also detected when KCl was replaced by N-methyl- d-glucamine-HCl. Under asymmetrical N-methyl-d-glucamine-HCl conditions, only anionic channels were observed. They exhibited current rectification (35 pS at negative voltages and 81 pS at positive voltages) and were strongly voltage-dependent. |
| Wosid | WOS:000087938800007 |
| Url | http://www.ncbi.nlm.nih.gov/htbin-post/Entrez/query?db=m&form=6&dopt=r&uid=10821741 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Keyword | Animal; Anions; Barium; pharmacology; Cesium; Electric Conductivity; Gluconates; Intestines; Ion Channels; physiology; Lipid Bilayers; metabolism; Meglumine; Membrane Fusion; Microvilli; Moths; Potassium Chloride; Support; Non-U.S.Gov't |
| Is Qa | No |