Normal Ca2+ signalling in glutathione-depleted and dithiothreitol-treated HeLa cells.
We have investigated whether reducing agents and substances that interfere with glutathione metabolism would affect the histamine-induced rises in internal Ca2+ concentration ([Ca2+]i) in indo-1-loaded HeLa cells. Individual cells responded to 1 microM histamine with either baseline or sinusoidal Ca2+ oscillations, a single Ca2+ peak or a maintained elevation of the [Ca2+]i. Only a few cells did not respond. The sulphydryl reducing agent dithiothreitol (5 mM) did not affect these responses to histamine. A 24-h preincubation with 1 mM DL-buthionine (SR)-sulphoximine, which reduces the cellular glutathione content to less than 20% of its control value, affected neither these histamine responses, nor the [Ca2+]i rises after application of 2 microM thapsigargin. We conclude that oxidation of critical sulphydryl groups is not required for the normal response to histamine and also that glutathione plays no role in agonist-induced Ca2+ signalling in HeLa cells.
Missiaen
L
L
Laboratorium voor Fysiologie, K. U. Leuven Campus Gasthuisberg, Belgium.
Parys
J B
JB
Bootman
M D
MD
De Smedt
H
H
Droogmans
G
G
Casteels
R
R
D000963:Antimetabolites / Q000494:pharmacology; D019328:Buthionine Sulfoximine; D002118:Calcium / Q000502:physiology*; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D004229:Dithiothreitol / Q000494:pharmacology*; D005978:Glutathione / Q000378:metabolism / Q000502:physiology*; D006367:HeLa Cells; D006632:Histamine / Q000494:pharmacology; D006636:Histamine Release / Q000187:drug effects; D006801:Humans; D008717:Methionine Sulfoximine / Q000031:analogs & derivatives / Q000494:pharmacology; D008856:Microscopy, Fluorescence; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D013729:Terpenes / Q000494:pharmacology; D019284:Thapsigargin
D000963:Antimetabolites; D013729:Terpenes; D008717:Methionine Sulfoximine; D019328:Buthionine Sulfoximine; D019284:Thapsigargin; D006632:Histamine; D005978:Glutathione; D002118:Calcium; D004229:Dithiothreitol