Adrenergic regulation of [3H]ketanserin binding sites during immobilization stress in the rat frontal cortex.
Acute immobilization stress increased serotonin and 5-hydroxyindoleacetic acid levels, the 5-hydroxyindoleacetic/serotonin ratio, and the number of [3H]ketanserin binding sites, representing serotonin-2 type receptors, in the rat frontal cortex. Peripheral administration of propranolol or central administration of 6-hydroxydopamine abolished the stress induced elevation of [3H]ketanserin binding sites. Treatment with 6-hydroxydopamine did not affect the increase in serotonin and 5-hydroxyindoleacetic acid levels, and enhanced the increase in the 5-hydroxyindoleacetic acid/serotonin ratio produced by stress. Conversely, chemical serotoninergic denervation with 5,7-dihydroxytryptamine had no influence on the stress-induced elevation of [3H]ketanserin binding sites, but abolished the serotonin and 5-hydroxyindoleacetic acid increase produced by stress. These results suggest that an intact serotoninergic system is not essential for serotonin-2 type receptor regulation during stress. Instead, the noradrenergic system, most probably through stimulation of beta-adrenoreceptors, may control the regulation of [3H]ketanserin binding sites in the rat frontal cortex during acute stress.
Institute of Experimental Endocrinology, CPS, SAS, Bratislava, Czechoslovakia.
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T
Torda
K
K
Murgas
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E
Cechova
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A
Kiss
J M
JM
Saavedra
D000818:Animals; D001665:Binding Sites / Q000187:drug effects*; D002540:Cerebral Cortex / Q000378:metabolism*; D003714:Denervation; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007650:Ketanserin / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D011433:Propranolol / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D012016:Reference Values; D012149:Restraint, Physical; D012701:Serotonin / Q000378:metabolism*; D013315:Stress, Psychological / Q000378:metabolism*
D011985:Receptors, Serotonin; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D007650:Ketanserin; D011433:Propranolol; D009638:Norepinephrine