PT - JOURNAL ARTICLE AU - A. M. Blamire AU - D. C. Anthony AU - B. Rajagopalan AU - N. R. Sibson AU - V. H. Perry AU - P. Styles TI - Interleukin-1β-Induced Changes in Blood–Brain Barrier Permeability, Apparent Diffusion Coefficient, and Cerebral Blood Volume in the Rat Brain: A Magnetic Resonance Study AID - 10.1523/JNEUROSCI.20-21-08153.2000 DP - 2000 Nov 01 TA - The Journal of Neuroscience PG - 8153--8159 VI - 20 IP - 21 4099 - http://www.jneurosci.org/content/20/21/8153.short 4100 - http://www.jneurosci.org/content/20/21/8153.full SO - J. Neurosci.2000 Nov 01; 20 AB - The cytokine interleukin-1β (IL-1β) is implicated in a broad spectrum of CNS pathologies, in which it is thought to exacerbate neuronal loss. Here, the effects of injecting recombinant rat IL-1β into the striatum of 3-week-old rats were followed noninvasively from 2 to 123 hr using magnetic resonance imaging and spectroscopy. Four hours after injection of IL-1β (1 ng in 1 μl), cerebral blood volume was significantly increased, the blood–brain barrier (BBB) became permeable to intravenously administered contrast agent between 4.5 and 5 hr, and the apparent diffusion coefficient (ADC) of brain water fell by 6 hr (5.42 ± 0.35 × 10−4 mm2/sec treated, 7.35 ± 0.77 × 10−4 mm2/sec control; p < 0.001). At 24 hr the BBB was again intact, but the ADC, although partially recovered, remained depressed at both 24 and 123 hr (p < 0.03). Depleting the animals of neutrophils before IL-1β injection prevented the BBB permeability at all time points, but the ADC was still depressed at 6 hr (6.64 ± 0.34 × 10−4 mm2/sec treated, 7.49 ± 0.38 × 10−4 mm2/sec control; p < 0.005). No changes were seen in brain metabolites using proton spectroscopy at 6 hr after IL-1β.Intraparenchymal injection of IL-1β caused a neutrophil-dependent transient increase in BBB permeability. The presence of neutrophils within the brain parenchyma significantly contributed to the IL-1β-induced changes in cerebral blood volume and the ADC of brain water. However, IL-1β apparently had a direct effect on the resident cell populations, which persisted well after all recruited leukocytes had disappeared. Thus the action of IL-1β alone can give rise to magnetic resonance imaging-visible changes that are normally attributed to alterations to cellular homeostasis.