Receptor and Carrier Regulated Transport of Na + -Valproate in Primary Astroglial Cultures

Abstract

Astrocytes play a crucial role in the processing and regulation of neuronal communicating mechanisms (1–3). Their processes surround capillaries and synapses, form the subpial and subependymal layers, and seemingly cover every neuronal surface not covered by other neuronal or oligodendroglial membranes (4). Thus, astrocytes are important for normal brain physiology. Astrocytes have also been shown to be involved in many pathological conditions in the brain. Research efforts in this area had previously concentrated only on the neurons, but in recent years data have been presented which show that astrocytes also have important roles. Different biochemical mechanisms of the astrocytes can be affected, depending on the pathological situation. Some important examples are epilepsy (defects in potassium buffering and changes in neurotransmitter metabolism; 5), Huntington's disease (production of toxic agents from enzymatic degradation; 6), and brain oedema (increased activity of ion transport systems; 7). Thus, since there is astrocytic involvement in brain disorders, the next and very important question is: is it possible to reach these cells with pharmacological treatment? To get somewhat closer to the answer to this question, the use of an adequate model system and model substance are necessary. The use of primary astroglial cultures from newborn rats provides obvious advantages.