Intracellular Oxidant Activity, Antioxidant Enzyme Defense System, and Cell Senescence in Fibroblasts with Trisomy 21

Table 1

Effect of prooxidants on cell viability.

Treatment	Low passages		High passages
	CF	T21F	CF	T21F
Untreated	100.0 ± 3%	100.0 ± 3%	100.0 ± 3%	100.0 ± 2%
AAPH	97.8 ± 2%	99.1 ± 3%	98.0 ± 3%	95.1 ± 2%
TBHP	93.0 ± 2%	93.7 ± 2%	96.1 ± 2%	89.0 ± 2%^a

Control ( = 5) and trisomy 21 ( = 5) fibroblasts were grown in 96-well microplates and incubated for one hour with Hank’s buffered salt solution (HBSS) (untreated) or supplemented with 10 mM AAPH or 100 M TBHP. Cell viability was determined by XTT assay and expressed as a percentage of XTT reduction compared with untreated fibroblasts. Values are expressed as mean ± SEM of six separate experiments performed in quadruplicate. Statistical differences between low- and high-passage groups were analyzed by Student’s -test; ^a < 0.01.