beta-Amyloid[1-40]-induced early hyperpolarization in M26-1F cells, an immortalized rat striatal cell line.
The short-term (20-minute) action of beta[1-40]-amyloid on the resting transmembrane potential was investigated by means of flow-cytofluorimetric studies in M26-1F cells, an immortalized rat striatal cell line, using the potential-sensitive fluorescent probe bis-oxonol. The distribution of the individual cell-associated probe fluorescence was found to be shifted to lower levels in cells treated with beta-amyloid[1-40] for 20 minutes as compared with that of their untreated counterparts. A change in the same direction was caused by valinomycin, a hyperpolarizing ionophore, whereas gramicidin, a depolarizing ionophore, induced a shift to higher fluorescence intensities. These findings, together with the reported behaviour of this particular fluorescent probe at different transmembrane potential levels, indicate that beta-amyloid[1-40] is capable of inducing early hyperpolarization in M26-1F cells. This is one of the earliest cell physiological effect of beta-amyloid peptides that has been reported so far. Moreover, our findings indicate an ionophore-like action of amyloid peptides.
Laskay
G
G
Department of Botany, University of Szeged, Hungary.
Zarándi
M
M
Jost
K
K
Penke
B
B
Bálint
E
E
Ocsovszki
I
I
Tarcsa
M
M
Várszegi
S
S
Gulya
K
K
D000483:Alleles; D016229:Amyloid beta-Peptides / Q000494:pharmacology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics; D002461:Cell Line, Transformed; D016764:Cell Polarity / Q000187:drug effects*; D003342:Corpus Striatum / Q000166:cytology*; D004058:Diffusion; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000493:pharmacokinetics; D006096:Gramicidin / Q000494:pharmacology; D007476:Ionophores / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D013696:Temperature; D013858:Thiobarbiturates / Q000493:pharmacokinetics; D014634:Valinomycin / Q000494:pharmacology
D016229:Amyloid beta-Peptides; D000900:Anti-Bacterial Agents; D000952:Antigens, Polyomavirus Transforming; D005456:Fluorescent Dyes; D007476:Ionophores; D010446:Peptide Fragments; D013858:Thiobarbiturates; C078592:amyloid beta-protein (1-40); D006096:Gramicidin; D014634:Valinomycin; C025284:bis(1,3-diethylthiobarbiturate)trimethineoxonol