Toxic effects of ozone on murine L929 fibroblasts. Damaging action on transmembrane transport systems.
Exposure of murine L929 fibroblasts to ozone caused inactivation of the energy-coupled transport systems for 2-aminoisobutyric acid and Rb+. Ozone induced an increase of the apparent Km for 2-aminoisobutyric acid transport, with a constant Vmax, indicating impairment of the carrier function, rather than a decrease in the number of transport sites. The uptake rate of 2-deoxy-D-glucose, on the other hand, increased after exposure of the cells to ozone. This was caused by an increased Vmax. of facilitated diffusion, without increased after ozone exposure. Together with the K+ leakage described previously, this reflects ozone-induced impairment of the barrier function of the membrane.
Van der Zee
J
J
Sylvius Laboratories, Department of Medical Biochemistry, Leiden, The Netherlands.
Dubbelman
T M
TM
Van Steveninck
J
J
D000621:Aminoisobutyric Acids / Q000378:metabolism; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D003847:Deoxyglucose / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects*; D005947:Glucose / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D051379:Mice; D010126:Ozone / Q000494:pharmacology*; D012413:Rubidium / Q000378:metabolism
D000621:Aminoisobutyric Acids; C100049:2-aminoisobutyric acid; D010126:Ozone; D003847:Deoxyglucose; D005947:Glucose; D012413:Rubidium