Cerebral Glucose Utilization in Rats is Not Altered by Hindlimb Restraint or by Femoral Artery and Vein Cannulation

Abstract

The effects of immobilization and femoral artery and vein cannulation on resting rates of local cerebral glucose utilization (LCGU) were measured in 35 brain regions of awake rats by using the quantitative, autoradiographic [¹⁴C]2-deoxy-D-glucose ([¹⁴C]DG) technique. Three groups of rats were cannulated on the previous day, and LCGU was measured under conditions of no restraint, 4 h of hindlimb restraint, or acute, four-limb immobilization. A fourth group represented the conventional preparation for [¹⁴C]DG experiments, with same-day cannulation followed immediately by 4 h of hindlimb restraint. Plasma catecholamines, corticosterone, and glucose concentrations were measured in all groups; all were elevated significantly above values in unrestrained animals only during four-limb immobilization. LCGU was unchanged by same-day surgery, hindlimb restraint, or both. During four-limb immobilization, LCGU was reduced by 25% in the dorsal hippocampus, and to a lesser extent in the anteroventral thalamic nucleus. It was increased only in the lateral habenula (42%). We conclude that two stressors of the experimental preparation (same-day surgery and hindlimb restraint) do not influence LCGU measurements by the [¹⁴C]DG method. More severe, acute stress selectively alters LCGU in a few rat brain regions.