FIG. 2.

Irradiation of the salivary glands results in endothelial cell apoptosis and a decrease in microvessel density (MVD) attenuated by treatment with Tempol during irradiation. Panel A: Immunofluorescence staining of mouse SGs 4 h after 15 Gy irradiation of the head and neck region. SGs were stained with anti-CD31 and anti-cleaved caspase-3 antibodies. Panel B: Quantification of apoptosis in the microvasculature of the SG at 4 h postirradiation (shown in panel A). **P < 0.001. Panel C: The average number of CD31⁺ endothelial cells in the control and Tempol-treated groups was significantly higher compared to the radiation only treatment group 4 h after exposure. CD31⁺ cells in SGs with 95% CIs are shown in a box plot. The upper boundary of the box represents the 75th percentile of the number of double positive per field per mouse. The lower boundary of the box represents the 25th percentile of the data distribution. The horizontal line within the box represents the median value and the error bars represent the 95% CIs. The closed circles above and below the bars represent out-of-range values. A total of 12 glands from six mice in each treatment group were studied, and 40 fields per gland were counted.