Modulation of whole-cell currents in Plasmodium falciparum-infected human red blood cells by holding potential and serum.
Recent electrophysiological studies have identified novel ion channel activity in the host plasma membrane of Plasmodium falciparum-infected human red blood cells (RBCs). However, conflicting data have been published with regard to the characteristics of induced channel activity measured in the whole-cell configuration of the patch-clamp technique. In an effort to establish the reasons for these discrepancies, we demonstrate here two factors that have been found to modulate whole-cell recordings in malaria-infected RBCs. Firstly, negative holding potentials reduced inward currents (i.e. at negative potentials), although this result was highly complex. Secondly, the addition of human serum increased outward currents (i.e. at positive potentials) by approximately 4-fold and inward currents by approximately 2-fold. These two effects may help to resolve the conflicting data in the literature, although further investigation is required to understand the underlying mechanisms and their physiological relevance in detail.
Staines
Henry M
HM
University Laboratory of Physiology, Parks Road, Oxford OX1 3PT, UK. henry.staines@physiol.ox.ac.uk
Powell
Trevor
T
Ellory
J Clive
JC
Egée
Stéphane
S
Lapaix
Franck
F
Decherf
Gaëtan
G
Thomas
Serge L Y
SL
Duranton
Christophe
C
Lang
Florian
F
Huber
Stephan M
SM
D000818:Animals; D001798:Blood Proteins / Q000494:pharmacology; D004553:Electric Conductivity; D004912:Erythrocytes / Q000469:parasitology* / Q000502:physiology*; D006801:Humans; D016778:Malaria, Falciparum / Q000503:physiopathology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D010963:Plasmodium falciparum
D001798:Blood Proteins