Kinetic Modeling Reveals the Roles of Reactive Oxygen Species Scavenging and DNA Repair Processes in Shaping the Dose-Response Curve of KBrO₃-Induced DNA Damage

Figure 6

Dose-response of genotoxic events in the kidney of rats exposed to KBrO₃. Data on kidney were selected as the kidney is the target organ of KBrO₃ carcinogenicity. (a) Data on 8-OH-dG levels in DNA extracted from the kidneys of rats exposed to KBrO₃ [9] are plotted versus KBrO₃ concentration. Data are fitted with a quadratic model with a zeroed linear term. (b) Deletion mutations in the kidneys of gpt delta rats exposed to KBrO₃. Dose-response data from Umemura et al. [21] are plotted. An exponential, low dose linear, model ([22, model 2]) is fit to the data for Spi⁻ mutation frequency as a measure of deletion mutations. A lognormal distribution of the data at each concentration was assumed and a log-scale constant variance model was used.

(a)

(b)