Presynaptic Muscarinic Receptors: Change of Sensitivity During Long-Term Drug Treatment
It is widely accepted that the sensitivity of neurotransmitter receptors can be modified during long-term activation or blockade of these receptors by specific drugs. Desensitization of receptors occurs in general after long-lasting exposure to agonists, whereas reduced supply of the agonist transmitter to its receptors, as in the case of a chronic treatment with antagonist drugs, appears to cause receptor supersensitivity. These modifications of receptor sensitivity are likely to have important implications, both in the ethiology of some diseases of the nervous system and in the mechanism of action of drugs used in the treatment of these disorders. In view of these considerations, it is important to ascertain whether and in what conditions a given receptor system can undergo adaptive changes, since neurotransmitter receptors may not be all equally adaptable.
KeywordsDopamine Choline Acetylcholine Atropine Scopolamine
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- 4.Molenaar, P.C. and Polak, R.L. (1970): Br. J. Pharmacol. 40: 406–417.Google Scholar
- 10.Raiteri, M., Maura, G. and Versace, P. (1983): J. Pharmacol. Exp. Ther. 224: 679–684.Google Scholar
- 11.Raiteri, M., Leardi, R. and Marchi, R. (1984): J. Pharmacol. Exp. Ther. 228: 209–214.Google Scholar
- 13.Szerb, J.C. (1977): In Cholinergic Mechanisms and Psychopharmacology (ed) D.J. Jenden, Plenum Press, New York, pp. 49–60.Google Scholar