Effects of 2-deoxy-D-glucose on sympathetic nerve activity to interscapular brown adipose tissue

The effects on firing rate of sympathetic nerves to interscapular brown adipose tissue were measured after induction of intracellular glycopenia by peripheral or central administration of 2-deoxy-D-glucose (2-DG). Injection of 2-DG (250 mg/kg body wt) into the jugular vein rapidly suppressed the sympathetic activity, which declined 84% within 10 min after the injection. This suppression persisted for at least 40 min. Hyperglycemia did not affect the sympathetic activity but partially inhibited the suppressive effect of 2-DG injection. Acute vagotomy failed to block the suppressive effect of 2-DG. Injection of 2-DG (2.5 mg/rat) into the third cerebral ventricle suppressed the sympathetic activity. This suppression was followed by gradual recovery. Saline injection did not affect the sympathetic activity. We conclude that cellular glycopenia induced by injecting 2-DG peripherally or into the third cerebral ventricle suppresses the sympathetic activity to brown adipose tissue. The results are consistent with the hypothesis that an acute energy shortage decreases the thermogenesis in interscapular brown adipose tissue by suppressing sympathetic neural activation of this tissue.