Decline in plasma membrane Ca(2+)-ATPase activity and increase in cytosolic-free Ca2+ concentration of endotoxin-injected mice livers.
The present study describes the activity of Ca(2+)-ATPase in liver plasma membrane and cytosolic-free Ca2+ concentration ([Ca2+]i) in an individual vital cell in mouse liver 18 h after endotoxin administration. Ca(2+)-ATPase activity in liver plasma membrane in the poisoned mice was markedly decreased to 28% of that in the control. The membrane protein damage in liver was found mostly in the molecular weight (M.W.) regions near 60,000-150,000 in endotoxemic mice, and was markedly injured near 140,000 (M. W. of Ca(2+)-ATPase in liver plasma membrane). The level of [Ca2+]i in liver cells in endotoxin-poisoned mice was greater at 18 h postintoxication than that of the control. These findings suggest the possibility that the depression of Ca(2+)-ATPase activity in liver plasma membrane in mice may contribute to membrane damage caused by the endotoxin, and that the increase of [Ca2+]i in liver cytoplasm may partially explain various endotoxin-induced metabolic disorders.
Sakaguchi
S
S
First Department of Hygienic Chemistry, Tohoku College of Pharmacy, Sendai, Japan.
Tsutsumi
E
E
Yokota
K
K
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004731:Endotoxins / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008970:Molecular Weight; D012486:Salmonella typhimurium
D004731:Endotoxins; D000252:Calcium-Transporting ATPases; D002118:Calcium