Modulation of insulin receptors and catecholamines in rat brain in hyperglycemia and hyperinsulinemia.

Insulin receptor activity and its relationship with catecholamines and serotonin were investigated in rat whole brain membranes, synaptosomes and choroid plexus in alloxan induced short term and long term hyperglycemia and hyperinsulinemia. Insulin receptor activity was measured by [125I]insulin binding and catecholamines by high performance liquid chromatography with electrochemical detection. While choroid plexus insulin receptors modulate along with norepinephrine, dopamine and serotonin with the changes in insulin and/or plasma glucose levels, insulin receptor activity in synaptosomes and total membranes is not affected to a great extent except in long term hyperglycemia.