Therapeutic effect of nerve growth factor on canine cerebral infarction evaluated by MRI

Abstract

To explore therapeutic effect of nerve growth factor (NGF) on cerebral infarction by establishing canine middle cerebral artery occlusion (MCAO) infarct model. The magnetic resonance imaging (MRI) technology was used to study effects of NGF on cerebral infarction, and the results of MRI indexes (such as diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI)) were compared with the results of pathology, cell biology and molecular biology. The clinical manifestations of the canine infarction model treated by NGF were significantly improved within 7 days compared with control group. The therapeutic evaluation of NGF effect could be determine by canine cerebral infarction treated by NGF within 6 hours according to DWI and PWI. From 6 hours to 7 days, therapeutic evaluation of NGF could be determine by T1WI, T2WI and FLAIR. DWI and PWI could find the change of cerebral ischemia at the early stage, provide advantages for qualitative diagnosis of early-stage cerebral infarction and observation of efficacy in early treatment, initially showing that their great potential for NGF role on cerebral ischemia and mechanism.

Keywords: canine middle cerebral artery occlusion; diffusion-weighted imaging; magnetic resonance imaging; nerve growth factor; perfusion-weighted imaging.

Figure 1

The normal images of T2WI (A), FLAIR (B), T1WI (C) and DWI (D) from the same slice of canines’ brain.

Figure 2

(A) 24 hours after cerebral ischemia, some microressels could be discerned on surface of cortex at the site of lesion; (B) 24 hours after cerebral ischemia, some lesion could be discerned on cortex.

Figure 3

(A) Comparison of the number of involved neurons in per view (HE staining × 400) among different group. (B) Comparison of the number of involved neuron synapses in per view (Electron Microscope × 4000) among different group.

Figure 4

(A) 6 hours after stroke, mitochondrion edema was seen (×20000) from different views; (B) 24 hours after stroke, mitochondrion edema was severe, the number of lipofascin paoticles were decreased (×20000) from different views.

Figure 5. Immunohistochemistry for NGF of canines’ brain

(A) The number of positive cells was increased gradually, and the degree of straining also was increased gradually; (B) The counts and degree of straining were more in those treated canine from group D (NGF treatment for 3 months).