Neuroprotection with intraventricular brain-derived neurotrophic factor in rat venous occlusion model.

Abstract

The increasing number of neurosurgical procedures for elderly patients and the development of skull base neurosurgery have increased interest in cerebral venous injury that might occur in a neurosurgical setting. Brain-derived neurotrophic factor (BDNF) may have neuroprotective effects against cerebral venous ischemia. To investigate the intraventricular effects of BDNF infusion on infarct size, suppression of apoptosis, and regional cerebral blood flow (rCBF) in cerebral venous ischemic lesions in a rat 2-vein occlusion model. Thirty-three male Wistar rats were randomly divided into BDNF-treated and vehicle control groups; each group was further randomly divided into 2-day and 7-day postocclusion groups. BDNF (2.1 μg/day) or vehicle was delivered continuously via intraventricular infusion pumps. Two adjacent contralateral cortical veins were then photochemically occluded. Two and 7 days after occlusion, we histologically measured ratios of infarct volume to contralateral hemisphere volume and counted (2-day group) terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL)-positive apoptotic cells in the penumbra. rCBF was measured via full-field laser perfusion imaging. The mean infarct volume after venous occlusion was significantly smaller in BDNF-treated rats than in controls at 2 days (1.49 ± 1.44% vs 3.66 ± 1.51%; P < .05) and 7 days (0.93 ± 0.47% vs 1.69 ± 0.58%; P < .05). Two days after occlusion, there were significantly fewer TUNEL-positive apoptotic cells in the BDNF-treated rats (17.0 ± 15.1) than in the controls (39.0 ± 19.6; P < .05). There were no differences in rCBF. After 2-vein occlusion, continuous intraventricular administration of BDNF protected the cerebral cortex against apoptosis and reduced infarct size without affecting rCBF.