Cerebral metabolism in fetal lamb after maternal infusion of ethanol.

Cerebral uptake of glucose and O2 (VCO2) was measured in 10 chronically catheterized fetal lambs during a control period, after a 1-h maternal infusion of ethanol (1.0 g X kg-1 X h-1) and 1-h postethanol infusion, to determine if alterations in cerebral metabolism might occur. Brachiocephalic artery and sagittal vein blood samples were analyzed for glucose, O2 content, blood gases, pH, and ethanol. Cerebral blood flow (Qc) was measured with a radioactive microsphere technique. VCO2 decreased significantly, from 140 +/- 13 mumol X 100 g-1 X min-1 during the control period to 91 +/- 8 (P less than 0.05) with the ethanol infusion, with a related fall in Qc, 177 +/- 12 to 104 +/- 9 ml X 100 g-1 X min-1 (P less than 0.001), the cerebral arteriovenous O2 difference being little changed. Cerebral glucose uptake, although decreased, was not significantly changed with the ethanol infusion, because the cerebral arteriovenous difference for glucose increased with the related fall in Qc. We conclude that maternal infusion of ethanol results in a decreased fetal VCO2 with a related fall in Qc. If prolonged, this decrease in cerebral oxidative metabolism might well affect cerebral development and provide a mechanism whereby chronic alcohol intake contributes to central nervous system growth anomalies and dysfunction of infants exposed to alcohol in utero.