Rotavirus infection alters Na+ and K+ homeostasis in MA-104 cells.
Infection of MA-104 cells with the OSU strain of rotavirus induced an increase in Na+ and a decrease in K+ intracellular concentrations, starting at 4 h post-infection. These changes were not related to an inhibition of the Na+/K+ pump since ouabain-sensitive 86Rb uptake was augmented in rotavirus-infected cells compared to control cells, whereas the [3H]ouabain binding and Na+/K+ ATPase activity in the cell homogenate were unaffected. Furosemide-sensitive 86Rb uptake (Na+/K+/2Cl- cotransport) was not modified by the infection. Passive 86Rb efflux and 22Na influx were augmented in infected cells suggesting an increase in the plasma membrane permeability. The increase in intracellular Na+ concentration might be responsible for the observed stimulation of the Na+/K+ pump. This effect was dependent upon the synthesis of viral proteins because it was abolished by addition of cycloheximide up to 4 h post-infection. Prevention of the increase in intracellular Na+ by the use of low Na(+)-containing media did not modify the pattern of protein synthesis. This suggests that changes in intracellular Na+ and K+ concentrations were not related to shutoff of cellular protein synthesis. Alterations of ion contents in the rotavirus-infected enterocytes might impair intestinal absorptive capacity before the appearance of histopathological lesions.
del Castillo
J R
JR
Laboratorio de Fisiología Gastrointestinal, Instituto Venezolano de Investigaciones Cientificas (IVIC), Caracas, Venezuela.
Ludert
J E
JE
Sanchez
A
A
Ruiz
M C
MC
Michelangeli
F
F
Liprandi
F
F
D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002460:Cell Line; D002463:Cell Membrane Permeability; D003513:Cycloheximide / Q000494:pharmacology; D005665:Furosemide / Q000494:pharmacology; D006706:Homeostasis; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000378:metabolism*; D012401:Rotavirus / Q000502:physiology*; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D014764:Viral Proteins / Q000096:biosynthesis
D014764:Viral Proteins; D010042:Ouabain; D005665:Furosemide; D003513:Cycloheximide; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D011188:Potassium