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Effect of Chronic Administration of Haloperidol (Intermittently) and Haloperidol‐Decanoate (Continuously) on D 2 Dopamine and Muscarinic Cholinergic Receptors and on Carbachol‐Stimulated Phosphoinositide Hydrolysis in the Rat Striatum
Author(s) -
Akiyama Kazufumi,
Sato Mitsumoto,
Yamada Norihito,
Otsuki Saburo
Publication year - 1987
Publication title -
psychiatry and clinical neurosciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.609
H-Index - 74
eISSN - 1440-1819
pISSN - 1323-1316
DOI - 10.1111/j.1440-1819.1987.tb00417.x
Subject(s) - apomorphine , haloperidol , carbachol , chemistry , muscarinic acetylcholine receptor , stereotypy , endocrinology , dopamine receptor , medicine , striatum , oxotremorine , spiperone , pharmacology , receptor , dopamine , dopaminergic , biochemistry , amphetamine
It has been reported that apomorphine‐induced stereotypy is sensitized after a chronic intermittent administration of haloperidol (HPD), but not after a chronic continuous exposure to haloperidol‐decanoate (HPD‐D). The present study was undertaken to investigate changes in the D 2 dopamine and muscarinic receptors in the ratstriatum after the administration of HPD intermittently and HPD‐D continuously. The number of striatal [ 3 H] spiperone binding sites increased significantly after HPD‐D, but did not change after HPD. Neither the number of [ 3 H](–)QNB binding sites nor carbachol‐stimulated phosphoinositide hydrolysis changed after either HPD or HPD‐D. These results indicate that the increase in striatal D 2 receptors in rats administered HPD‐D represents behavioral and biochemical tolerance, and that neither the D 2 dopamine receptor supersensitivity nor muscarinic receptor hyposensitivity underlies sensitization of apomorphine‐induced stereotypy.