Animals were anesthetized with an intraperitoneal injection of 0.75-1.5 ml/kg of a solution containing 2/3 ketamine

(100 mg/ml) (Clorketam®, Vétoquinol, Lure, France) and 1/3 xylazine (20 mg/ml) (Rompun®, Bayer, Puteaux, France). Rats were placed in a small-animal stereotaxic frame (Kopf Instruments, Phymep, France). After shaving and disinfection of the skin, a sagittal incision of selleck chemicals 2 cm was made to expose the skull, followed by a burr hole 0.5 mm anterior and 3 mm lateral from the bregma using a small drill. Following trypsinisation (trypsin/EDTA (Sigma)) and resuspension in “”EMEM”" (“”Eagle’s Minimum Essential Medium”", Biowhittaker), 10 μl of 103 9L-cells in suspension were implanted 5 mm deep in the right striatum (according to the Paxinos

atlas) using a 10 μl -26G Hamilton syringe (Harvard Apparatus, Ulis, France). After waiting 5 minutes, the needle was removed and the wound was sutured with absorbable surgical thread. Rats bearing 9L tumor were randomized to either the “”untreated”" group (group A) or the group irradiated by a whole-brain irradiation (WBI) to a total dose of 18 Gy (group B). The radiotherapy started on day 8 after the tumor cell implantation when the tumor size was 10-15 μl [14]. Radiotherapy protocol Rats were irradiated using a 6-MV linear accelerator (Saturn 41 type, Varian Medical Systems, Salt Lake City, USA), under mild anaesthesia by isoflurane (4.5% during 2 minutes then 2% for the treatment) + O2 3 L/min. Oxygen masks were connected and KU55933 clinical trial four rats were placed in a reproducible way, in a prone position on the linac couch with laser alignment. The WBI was delivered by one photon beam (6 MV-energy, DSP 100 and 4 Gy/min). The radiation field was 15 × 15 cm at source-axis distance of 100 cm. The isocenter was in the midline of the brain and the posterior limit of the field corresponded to the line passing by the posterior part of the 2 ears (Figure 1). Figure 1 Radiation therapy position. An equivalent tissue of

1.5 cm was laid on the rat head in order to improve the dose distribution in brain. A 15-mm thickness of equivalent tissue was laid on the rat’s head in order to improve dose distribution to the brain. The dose distribution was defined by the 4��8C Radiation Therapy department. Eighteen Gy, given in 3 fractions of 6 Gy were delivered over 7 days in the isocenter corresponding to the tumor (Figure 2). The brain was covered by the 95%-isodose. The irradiation was only started in the absence of wound healing problems (abscess, haematoma…) and if rat’s general state allowed it. After irradiation, animals were replaced in their cage. Control rats were also anesthetized according to the same schedule as the group B animals. Figure 2 Belnacasan price Therapeutic schedule. Animal observation Rats were examined daily and staged for activity and well-being according to a classification developed in our animal facility (data not published) (Table 2). Toxicities were noted.