Development of an intracerebral glioma model in whole body irradiated hairless rats.

AIMS: To study the in vivo radiosensitivity of malignant gliomas, an animal glioma model was developed using the implantation of glioma cell lines into the brain of the Hairless rat (a mutant from the Sprague-Dawley strain, characterised by its complete absence of hair). METHODS: 10(6) malignant cells were suspended in 10 microliters phosphate buffered saline (PBS) and injected at a 4 microns depth into the left frontal lobe of an anaesthetised animal through a small craniotomy hole without opening the dura mater. The glioma cell line C6 (obtained from a chemically-induced rat glioblastoma) was introduced into 11 animals, and the human glioblastoma line G5 into 12 animals. RESULTS: The tumour take was checked using histological criteria. It was poor: 0% for the G5 line and only 27.3% for the C6 line. To improve the tumour growth rate, rats were subjected to a single dose (3.5 Gray) total body irradiation, 24 hours prior to injection, causing a marked immunosuppression. 84.6% of the rats grafted with the C6 line then produced tumours. Similar results (75% tumour take) were obtained using a stereotactic inoculation of the tumour cells. CONCLUSIONS: Thanks to the contribution of whole body irradiation, an animal intracerebral glioma model was establish, which can be used for clinical and biological studies.