Intracellular calcium and pH alterations induced by Escherichia coli endotoxin in rat hepatocytes.
In this study, the fluorescent Ca2+ probe fura-2 and the fluorescent pH indicator BCECF have been used to monitor cytosolic free Ca2+ and intracellular pH (pHi), respectively, in isolated and cultured hepatocytes treated with Escherichia coli O111:B4 endotoxin. Uptake of 45Ca2+ was also measured to study the effect of endotoxin on the extracellular calcium influx. Endotoxin treatment produced a progressive increase of cytosolic Ca2+ in a dose-dependent manner caused by both induction of a significant release of Ca2+ from intracellular stores and stimulation of the extracellular calcium influx. The perturbation of Ca2+ homeostasis by endotoxin may cause an abnormal stimulation of physiological processes, developing lethal cell injury. Endotoxin also produced a significant decrease in the pHi of hepatocytes which can justify important metabolic alterations during endotoxicosis.
Portolés
M T
MT
Department of Biochemistry and Molecular Biology I, Faculty of Chemistry, Universidad Complutense, Madrid, Spain.
Ainaga
M J
MJ
Municio
A M
AM
Pagani
R
R
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D003600:Cytosol / Q000187:drug effects; D004731:Endotoxins / Q000494:pharmacology*; D004926:Escherichia coli; D005452:Fluoresceins; D016257:Fura-2; D006863:Hydrogen-Ion Concentration; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D004731:Endotoxins; D005452:Fluoresceins; C043829:2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein; D002118:Calcium; D016257:Fura-2