Figure 4.

(A and B) Igf1 increases cerebrocortical glucose uptake. Igf1 (A) or fibroblast growth factor 2 (FGF2) (B) was injected into the cerebral cortex of anesthetized rats with vehicle injected simultaneously into the contralateral side. After the cerebral injections, 2DG was administered i.p. and the animals were killed 45 min later. Representative film autoradiographs from sections at the injection site show that only Igf1 produced increases in 2DGU, which is readily appreciated along the needle track. These findings were replicated in three animals. (C and D) Parallel patterns for Igf1 expression (C) and ¹⁴C-2DGU (D) in the adult rat brain 6 days after middle cerebral artery occlusion. Other growth factors such as Igf2 and platelet-derived growth factor did not show a similar correlation with 2DGU (data not shown).