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Copyright © 1999 by Institute of Pharmacology Polish Academy of Sciences |
Pol. J. Pharmacol., 1999, 51, 179-186 ISSN 1230-6002 |
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Voltage-operated calcium channels: characteristics and their role in the mechanism of action of psychotropic drugs.
L. ANTKIEWICZ-MICHALUK. Pol. J. Pharmacol., 1999, 51, 179-186. Ion channels can be divided in two main groups, receptor-operated channels (ROC) and voltage-operated channels (VOC). The function of ROC depends on the action of agonists and antagonists, the function of VOC is closely connected with the activity of enzymes and the processes of phosphorylation of membrane proteins. Electrophysiological studies indicate the existence of three types of VOC (K+, Na+, Ca2+ channels). In number of neurons various subtypes of Ca2+ channels (P, T, N and L-type) occur together. Among them, the L-type Ca2+ channel has been first described and most studied. The L-type calcium channel is localized on nerve terminals in the pre- and postsynaptic parts, as well as on cell bodies and may be involved in the mechanism of action of psychotropic drugs. Our own experiments have shown that chronic treatment with various psychotropic drugs changes the density of L-type Ca2+ channels in the central nervous system. We have found the involvement of L-type VOC in responsiveness to pain, morphine tolerance and dependence, and adaptation changes induced by several chronic administration of psychotropic drugs. Thus, according to pharmacological and also clinical data, L-type Ca2+ channels may be involved in etiology of variety of psychiatric disorders. Key words: voltage-operated channels, dihydropyridines, morphine analgesia, morphine dependence, antidepresants, psychiatric illness |
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