In rhEPO-treated rats, mean haematocrit showed a 25% increase from 50.7��0.4% before therapy to 62.6��0.4% on day 8 (P<0.001, Student's t-test). In the control group, haematocrit values remained unchanged. Effects of rhEPO on tumour growth The present experiment was intended to detect early microvascular changes after selleck chemicals Sorafenib fractionated RT and not to study the effects of rhEPO on tumour growth or modulation of RT effects on tumour growth. Administration of rhEPO was therefore started after a tumour had developed. Tumour volume before RT was 1��0.2cm3 in the control group and 0.97��0.11cm3 in the rhEPO group (P=0.79, Mann�CWhitney U-test). After RT, tumour volume was 0.99��0.2cm3 in the control group and 0.99��0.16cm3 in the rhEPO group (P=0.99, Mann�CWhitney U-test).

Effects of rhEPO on RT-induced tumour microvascular changes Pixel-by-pixel kinetic modelling encompassing both the tumour core and rim was performed with estimation of three microvascular parameters: plasma flow Fp, permeability surface product PS, and fractional plasma volume Vp. Results of DCE-MRI microvascular data modelling are shown in Figure 3. Microvascular plasma flow in the tumour core of control rats was significantly lower after RT (P<0.001, Student's t-test). No significant effect of RT was noted in the tumour rim of control animals. In rhEPO-treated rats, microvascular flow in the tumour core was also significantly lower after RT (P<0.001, Student's t-test) but unaffected in the tumour rim. The magnitude of the RT effect on tumour core flow did not differ significantly between control and rhEPO-treated animals (33 vs 23% decrease, respectively, P=0.

11, Fisher’s exact test). Figure 3 Results of kinetic modelling of DCE-MRI data. (A) Example of parametric maps of the permeability surface product (PS) in control animals and rhEPO-treated animals before and after RT. The tumour is masked and the arrow points to the pixel containing the … In control animals, the microvessel PS was significantly lowered by RT in the tumour rim (P<0.001, Student's t-test) but not in the tumour core. In rhEPO-treated animals, however, PS was not affected by RT. Fractional plasma volume was significantly lower in both the tumour core and rim in control animals after RT (P<0.001, Student's t-test). In rhEPO-treated animals, however, no significant changes in plasma volume were noted after RT.

Effects of rhEPO on tumour pO2 and LDF Oxygenation and LDF measurements were performed before and 5 days after completion of fractionated RT. Mean pO2 values in the tumour core and peripheral rim before and after RT in both groups are shown in Figure 4A and B. Oxygenation was significantly better in the tumour rim compared with the tumour core of Cilengitide all animals (data not shown). In the control group, RT induced a reoxygenation in the tumour core (P=0.