Abstract
The interaction between corticosterone and hippocampal 5-HT1A receptor mRNA expression was investigated in male rats. Two days after adrenalectomy, 5-HT1A receptor mRNA was increased in the granule cell layer of the dentate gyrus. Injection of corticosterone led to a significant dose-dependent and transient suppression of 5-HT1A receptor mRNA. The effect of a low dose of corticosterone (50 micrograms/kg) could be blocked by RU 28318, a specific mineralocorticoid receptor antagonist, but not by RU 38486, a glucocorticoid antagonist. The effect of a higher dose of corticosterone (300 micrograms/kg) could be partially blocked by RU 28318, whereas there was no additional effect of RU 38486. These results point to a stringent regulation of hippocampal 5-HT1A receptors by corticosterone that is predominantly mediated by the mineralocorticoid receptor.
MeSH terms
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Adrenalectomy
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Animals
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Corticosterone / pharmacology*
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Densitometry
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Dose-Response Relationship, Drug
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Gene Expression Regulation / drug effects
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Hippocampus / drug effects
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Hippocampus / metabolism*
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In Situ Hybridization
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Male
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Mifepristone / pharmacology
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Mineralocorticoid Receptor Antagonists / pharmacology
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RNA, Messenger / biosynthesis*
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Rats
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Rats, Wistar
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Receptors, Glucocorticoid / drug effects
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Receptors, Glucocorticoid / genetics
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Receptors, Glucocorticoid / metabolism
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Receptors, Mineralocorticoid / drug effects
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Receptors, Mineralocorticoid / genetics
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Receptors, Mineralocorticoid / metabolism*
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Receptors, Serotonin / biosynthesis*
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Spironolactone / analogs & derivatives
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Spironolactone / pharmacology
Substances
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Mineralocorticoid Receptor Antagonists
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RNA, Messenger
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Receptors, Glucocorticoid
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Receptors, Mineralocorticoid
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Receptors, Serotonin
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Spironolactone
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Mifepristone
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RU 28318
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Corticosterone