The research findings, from the University of Pittsburg,h explain that antipsychotic drugs that block dopamine signalling function in the brain (as intended) and also in the pancreas (by association). The pancreas produces beta cells, which generate and release the blood-sugar-lowering molecule insulin.
Dopamine is a molecule that triggers signals passing from one neuron to another (what is termed a neurotransmitter). The chemical also plays a part in brain functions associated with learning, motivation, and pleasure. These are in the form of reward-motivated behaviour pathways. Many drugs used as a medication for psychiatric conditions (clozapine, haloperidol, and olanzapine) are designed to block the pathway.
The following video explains more about the processes involved:
It seems that the alternation with dopamine signalling leads to the uncontrolled production. The metabolic conditions associated with this are diabetes and obesity. Hence the researchers allude to a dopamine theory of metabolism, making the case for not only study the effects of the drug on the brain but also on the rest of the human body.
This means that when glucagon or insulin producing cells become dysfunctional, then conditions like high blood glucose can arise and metabolic disease as well as cardiovascular complications. Hence there is an important correlation between metabolic syndrome and schizophrenia, and this is impacted by antipsychotic treatments.
Lead researcher Dr. Despoina Aslanoglou says that this understanding could mean additional treatment for patients in terms of addressing these side-effects. He tells Laboratory Roots: “Our discovery can inform us of how to better formulate drugs to target dopamine signaling. This might be a novel pathway to therapeutics in both psychiatry and metabolism.”
The research has been published in the journal Translational Psychiatry. The study is titled “Dopamine regulates pancreatic glucagon and insulin secretion via adrenergic and dopaminergic receptors.”