Effects of lethal dose of γ-radiation and partial body hyperthermia on Wistar rats

Figures & data

Figure 1. Kaplan-Meiersurvival curves illustrating 30 days survival of 200 -g Wistar male and female rats subjected to 9-Gy whole body gamma irradiation and treated with partial body hyperthermia (PBH) 20 h prior to irradiation. According to Log-rank (Mantel-Cox) test, control vs. 9 Gy male, p < 0.0001; control vs. 9 Gy female, p < 0.0001; 9 Gy 200g male vs. PBH male, p < 0.001; 9 Gy 200g female vs. PBH female, p < 0.001.

Table 1. Time-mortality responses of Wistar male and female rats subjected to 9 Gy whole body gamma irradiation and treated with partial body hyperthermia (PBH) 20 h prior to irradiation.

Treatments	LT99 (95% FL) (d)	Slope ± SE	Intercept ± SE	X^2 (df)^2
♂ 9 Gy (control)^1	13.67 (11.97–16.80)^b	0.37 ± 0.02	−2.72 ± 0.18	29.13 (6)
♂ 200 g, 9 Gy + PBH	33.94 (27.53–47.84)^a	0.11 ± 0.01	−1.29 ± 0.10	39.18 (8)
♂ 250 g, 9 Gy + PBH	24.1 (19.57–35.22)^a	0.16 ± 0.01	−1.59 ± 0.10	94.37 (8)
♀ 9 Gy (control)	8.63 (8.21–9.21)^c	0.98 ± 0.95	−6.15 ± 0.60	2.69 (3)
♀ 200 g, 9 Gy + PBH	25.12 (21.18–32.87)^a	0.16 ± 0.01	−1.65 ± 0.11	56.01 (8)
♀ 250 g, 9 Gy + PBH	19.00 (15.83–26.27)^ab	0.24 ± 0.01	−2.18 ± 0.13	105.46 (8)

FL, fiducial limit; SE, standard error; d, days; df, degrees of freedom.

¹Irradiation was carried out on rats weighing 200 g (50%) and 250 g (50%).

²The X² values for goodness-of-fit of the probit regression model to the observed mortality data were significant (p < 0.05), except for 9-Gy irradiated females; indicating that the response of Wistar rats to gamma irradiation and PBH treatments was heterogeneous.

^a,b,cLT₉₉ values in column for each animal groups followed by the same letters are not significantly different based on the overlap of their 95% fiducial limits.

Figure 2. Recovery of bone marrow cells of Wistar male and female rats subjected to 9-Gy whole body gamma irradiation and treated with partial body hyperthermia (PBH) 20 h prior to irradiation. Error bars represent the mean ± SEM. Significant differences were found between treatments on day 21 post-irradiation (F = 1936; df = 4, 70; p < 0.0001), ANOVA followed by PLSD.