Effect of 14-day osmotic pump infusion of 5 mM gamma-linolenic acid (GLA) or control cerebrospinal fluid (CON = CSF) on C6 glioma development in vivo. (A) Tumour size estimated by glial fibrillary acidic protein labeling and image analysis with ImageProPlus. Average tumour area (mm2) and length = rostral-caudal extension (mm) were plotted for CON (control CSF) and GLA (5 mM GLA + CSF) (n = 12), statistical significance, * = p < 0.0001. Left side of graph presents area (CON A and GLA A) while right side of graph presents length (CON L and GLA L). (B and F) mRNA expression of VEGF and Flt-1 in CON and GLA-treated tumours, with GAPDH as an internal control (n = 10), statistical significance, * = p < 0.001. (D and G) Immunohistochemical labeling for VEGF and Flt-1 CON and GLA-treated tumours, semi-quantitative analysis with ImageProPlus. (n = 9), statistical significance, * = p < 0.01 (C and E) Fatty acid composition by gas chromatography-mass spectrometry of CON (C) and GLA (E) treated tumours (n = 11), statistical significance, * = p < 0.0001. (H-J) Representative images of control (H), VEGF (I) and Flt-1 (J) immunohistochemical labeling (n = 9).