Effect of hypocapnia on local cerebral glucose utilization in rats

Anesthesiology. 1989 Mar;70(3):523-6. doi: 10.1097/00000542-198903000-00024.


The effect of hypocapnia on regional cerebral glucose utilization (L-CMRg) was studied in 14 Sprague Dawley rats. After cannulation of femoral vessels, halothane was discontinued and anesthesia was maintained with 70% N2O in oxygen. The animals' lungs were mechanically ventilated to achieve normocapnia (PaCO2 = 40 +/- 2 mmHg) in group A or hypocapnia (PaCO2 = 25 +/- 2 mmHg) in group B. L-CMRg was measured by the 14C-2-deoxyglucose autoradiographic method. Twenty-six anatomically discrete structures representing cortical, subcortical, limbic, and brainstem areas were studied. In hypocapnic animals, mean values for L-CMRg were higher in 25 out of 26 structures studied. The increase in L-CMRg was heterogenous. The structures that had higher L-CMRg during normocapnia showed the greatest increase in L-CMRg. When the two groups were compared using a profile analysis, in six regions (lateral and ventral thalamus, inferior colliculus, lateral habenulla, medial geniculate body, and auditory cortex), a value of P less than 0.05 was obtained.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Blood Glucose / analysis
  • Brain / metabolism*
  • Carbon Dioxide / blood
  • Carbon Dioxide / deficiency*
  • Carbon Radioisotopes
  • Deoxyglucose / blood
  • Glucose / metabolism*
  • Halothane
  • Male
  • Nitrous Oxide
  • Oxygen
  • Rats
  • Rats, Inbred Strains
  • Respiration, Artificial


  • Blood Glucose
  • Carbon Radioisotopes
  • Carbon Dioxide
  • Deoxyglucose
  • Glucose
  • Nitrous Oxide
  • Oxygen
  • Halothane