Exchange-mediated dilution of brain lactate specific activity: implications for the origin of glutamate dilution and the contributions of glutamine dilution and other pathways.

ABSTRACT: The magnitude of metabolic activation is greatly underestimated in autoradiographic studies using [1- or 6-14C]glucose compared to parallel assays with [14C]deoxyglucose indicating that most of the label corresponding to the additional [14C]glucose consumed during activation compared to rest is quickly released from activated structures. Label could be lost by net release of [14C]lactate from brain or via lactate exchange between blood and brain. These possibilities were distinguished by comparison of glucose and lactate specific activities in arterial blood and brain before, during, and after generalized sensory stimulation and during spreading cortical depression. Over a wide range of brain lactate concentrations, lactate specific activity was close to the theoretical maximum, i.e. half

SUBMITTER: Dienel GA 

PROVIDER: S-EPMC2756232 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature