Serum P-Glycoprotein Assessement in Neurologic and Complementary Pathologies

The blood-brain-barrier (BBB) is a dynamic interface that plays a crucial role in the communication patterns and regulatory pathways between CNS and periphery. The modulatory role of the BBB is largely mediated through specialized transport proteins expressed at the luminal and abluminal membranes of brain endothelial cells, in addition to the inter-endothelial tight junction proteins. The transporter proteins normally act to regulate endogenous molecules access across the BBB, by influx and efflux mechanisms. Current drug-delivery research attempts to manipulate these transporters to enhance the entry of therapeutic agents into the CNS, in this respect being of significant interest the P-glycoprotein (P-gp). This efflux protein expressed at the luminal surface of brain endothelial cells, has been referred to as the 'gatekeeper' at the BBB. The expression and function of P-gp has been reported to be altered in various neurological and peripheral disorders, including Alzheimer's disease, Parkinson's disease, epilepsy, HIV infection. The purpose of this research was to provide an overview of P-gp expression and function in different psychiatric and neurological diseases, complimentary to other pathologies: leukemia, rheumatoid arthritis, type 2 diabetes, acute pancreatitis and healthy pregnant women, and highlight the potential implications of P-gp in the physio-pathological coordinates and therapeutic barriers driven by any deviation from the neurologic homeostasis.