Glucose concentrations in brain and blood: regulation by dopamine receptor subtypes

The stimulation of D1 and D2 dopamine (DA) receptors by selective agonists produced large increases in brain glucose concentrations. D2 receptor stimulation also produced large increases in blood glucose. The D1-induced increases were somewhat variable in normal animals, but were more reliably observed and greatly increased in animals with brain DA depletions. Blockade of D1 receptors prevented these increases. Likewise, centrally acting D2 antagonists, but not the peripheral D2 antagonist domperidone, prevented D2 agonist-induced increases in brain and blood glucose. These observations point to an important role for DA in the regulation of glucose homeostasis.