Models of High-Grade Glioma in Rats: Morphology, Size, Thickness of Cerebral Cortex, and Survival

The sizes of intracerebral high-grade gliomas 101.8 and C6 in Wistar and Long-Evans rats and their relationship with survival were determined; changes in the thickness of the cerebral cortex were evaluated and morphological features of glioma models were studied. Median glioma volumes measured on MRI of brain slices in Wistar rats with glioblastoma 101.8 and glioma C6 were 169 (148-252) mm³ and 114 (47-154) mm³, respectively; in Long-Evans rats with glioma C6, the median volume of the tumor was 159 (85-223) mm³ without significant differences. The mean survival time of Wistar rats with glioblastoma 101.8 and glioma C6 were 16 ± 1 (SE = 0.3) days and 33 ± 6 (SE = 2) days; in Long-Evans rats with glioma C6, the mean survival time was 30 ± 2 (SE = 4) days. Survival in rats with glioblastoma 101.8 was significantly lower than in animals with C6 glioma. A negative correlation of tumor size and survival was revealed in Wistar and Long-Evans rats with glioma C6: r = -0.80 (p = 0.006) and r = -0.70 (p = 0.03), respectively. The mean thickness of the cortex of the contralateral hemisphere in tumor-bearing rats was significantly lower than in sham-operated animals. Glioma models vary in the growth rate. At the late stages of 101.8 and C6 gliomas, the thickness of the cerebral cortex of the contralateral hemisphere decreases. The volume of C6 glioma can be used as a predictor of Wistar and Long-Evans rat survival.