Regional variability of blood flow and glucose utilization within the subependymal germinal matrix

Regional cerebral blood flow (RCBF) and local cerebral glucose utilization (LCGU) were studied in normal, awake newborn beagle puppies using quantitative autoradiography. A highly significant linear relationship between RCBF and LCGU was present for all brain structures. Special attention was directed to the subependymal germinal matrix (GM), the site of origin of periventricular hemorrhage in the premature human. A consistent variability in both RCBF and LCGU was found within GM. Both RCBF and LCGU were higher in rostral than posterior GM, and in peripheral than internal GM. The close coupling between RCBF and LCGU within GM suggests that GM blood flow is influenced by local energy needs. The quantitative relationship between RCBF and LCGU was similar within GM to that in cerebral white and gray matter, suggesting that the puppy GM predominantly utilizes glucose as fuel for energy production.