| Autor: |
Lapaix F; Centre National de la Recherche Scientifique, UPR 9042, Station Biologique, Place GTeissier, BP74, 29682 Roscoff cedex, France., Egée S, Gibert L, Decherf G, Thomas SL |
| Jazyk: |
angličtina |
| Zdroj: |
Pflugers Archiv : European journal of physiology [Pflugers Arch] 2002 Oct; Vol. 445 (1), pp. 152-60. Date of Electronic Publication: 2002 Sep 07. |
| DOI: |
10.1007/s00424-002-0913-y |
| Abstrakt: |
The patch-clamp technique was used to demonstrate the presence of ATP-sensitive K(+) channels and Ca(2+)-activated K(+) channels in lamprey ( Petromyzon marinus) red blood cell membrane. Whole-cell experiments indicated that the membrane current under isosmotic (285 mosmol l(-1)) conditions is carried by K(+). In the inside-out configuration an ATP-sensitive K(+) channel (70-80 pS inward, 35-40 pS outward) was present in 35% of patches. Application of ATP to the intracellular side reduced unitary current with half-maximal inhibition in the range 10-100 microM. A block was obtained with 100 microM lidocaine and inhibition was obtained with 0.5 mM barium acetate. A Ca(2+)-activated K(+) channel (25-30 pS inward, 10-15 pS outward) was present in 57% of patches. Inhibition was produced by 10 mM TEA and 500 nM apamin and sensitivity to Ba(2+) was lower than for ATP-sensitive channels. No spontaneous channel activity was recorded in the cell-attached configuration under isotonic conditions. With hypotonic saline 68% of patches showed spontaneous single-channel activity, and, of 75 active patches, 66 cell-attached patches showed channel activity corresponding to Ca(2+)-activated K(+) channels. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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