Effects of blood sugar level on rat transient focal brain ischemia consecutively observed by diffusion-weighted EPI and (1)H echo planar spectroscopic imaging.

The effects of blood sugar level on transient focal brain ischemia were examined by consecutive diffusion-weighted EPI and (1)H echo planar spectroscopic imaging. A remote-controlled rat intraluminal suture middle cerebral artery occlusion (MCAO) model was prepared. Animals were divided into three experimental groups: control, 1 g/kg, and 2 g/kg glucose groups (n = 6 for each). Saline or glucose was infused intraperitoneally 30 min prior to MCAO. The glucose-loaded groups showed increased lactate accumulation and marked decreases in average diffusion coefficient in the ischemic region during 40-min MCAO. These changes were correlated with blood sugar levels at the onset of MCAO. After reperfusion, all rats in the control and 1 g/kg groups recovered from the ischemic changes, but three rats with marked hyperglycemia in the 2 g/kg group showed irreversible changes. The adverse effects of hyperglycemia on transient focal brain ischemia were clearly demonstrated by sequential 2D images. Magn Reson Med 42:895-902, 1999.