HIGH-VALENT Cr, Mn, AND Fe SPECIES - Oxidation of Amino Acids, Peptides, and Proteins: Kinetics and Mechanism - page 299

(a)

100
90
80
70
60
50

Lead Chromate
Barium Chromate
Zinc Chromate
Sodium Chromate

40
30

20
10
0 0

500 1000 1500 2000 2500 3000

Intracellular Chromium lon Concentration( µ M)

(b)

20
18
16

Lead Chromate
Barium Chromate
Zinc Chromate
Sodium Chromate

14
12

10
8

6

4
2
0

0 200 400 600 800 1000 1200 1400

Intracellular Cr lon Concentration ( µ M)

Figure 6.10. (a) The cytotoxic effect of all four compounds corrected for intracellular
chromium ion concentration. Barium chromate and zinc chromate were significantly
more cytotoxic than lead chromate and sodium chromate ( p < 0.005); there was no
significant difference between barium chromate and zinc chromate or between lead
chromate and sodium chromate. (b) All compounds induced similar levels of DNA
double-strand breaks at similar intracellular concentrations, for example, 500 µM intra-
cellular Cr induced three, four, five, and six average foci per cell after exposure to
barium chromate, zinc chromate, lead chromate, and sodium chromate, respectively
(adapted from Wise et al. [163] with the permission of the American Chemical Society).