Antioxidant enzymes and steroid-induced proliferation of kidney tubular cells.
Diethylstilbestrol induces proliferation of Syrian hamster renal proximal tubular cells. By counting the number of cells in culture, we showed that liposomes containing superoxide dismutase or catalase suppressed diethylstilbestrol-induced proliferation, whereas empty liposomes or liposomes containing inactivated superoxide dismutase did not. Liposomes containing antioxidant enzymes did not suppress proliferation of cells in control media or of cells treated with ethinyl estradiol. In the absence of liposomes, exogenous superoxide dismutase did not suppress diethylstilbestrol-induced proliferation. The decrease in cell number when diethylstilbestrol-treated cells were treated with antioxidant enzyme-containing liposomes was not due to decreased cell viability. Results were confirmed by measuring a correlate of cell proliferation immunohistochemically, using an antibody to proliferating cell nuclear antigen. A larger proportion of diethylstilbestrol-treated cells than of control cells showed nuclear immunostaining with this antibody. The number of cells immunostained in diethylstilbestrol-treated cultures was sharply decreased by the addition of superoxide dismutase- or catalase-containing liposomes. Our studies suggest a role for active oxygen species in diethylstilbestrol-induced proliferation of cultured proximal tubular cells.
Oberley
T D
TD
Laboratory Service, Pathology Section, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705.
Allen
R G
RG
Schultz
J L
JL
Lauchner
L J
LJ
D000818:Animals; D000975:Antioxidants; D002374:Catalase / Q000494:pharmacology*; D002452:Cell Count; D002455:Cell Division / Q000187:drug effects*; D002478:Cells, Cultured; D006224:Cricetinae; D004054:Diethylstilbestrol / Q000494:pharmacology*; D004997:Ethinyl Estradiol / Q000494:pharmacology; D005609:Free Radicals; D007684:Kidney Tubules / Q000187:drug effects / Q000254:growth & development* / Q000378:metabolism; D008081:Liposomes; D008647:Mesocricetus; D013482:Superoxide Dismutase / Q000494:pharmacology*
D000975:Antioxidants; D005609:Free Radicals; D008081:Liposomes; D004997:Ethinyl Estradiol; D004054:Diethylstilbestrol; D002374:Catalase; D013482:Superoxide Dismutase