PMID: 9166758Jun 1, 1997Paper

Down-regulation of 5-hydroxytryptamine7 receptors by dexamethasone in rat frontocortical astrocytes

Journal of Neurochemistry
M ShimizuS Yamawaki

Abstract

Astrocytes derived from rat frontal cortex contain 5-hydroxytryptamine7 (5-HT)7 receptors positively coupled to adenylyl cyclase. In the present study, we investigated the effects of glucocorticoids on adenylyl cyclase activity and 5-HT7 receptor gene expression in astrocytes. Addition of dexamethasone (0.01-100 nM, 12-72 h) to the culture medium decreased cyclic AMP formation induced by 5-HT in a time- and concentration-dependent manner. Dexamethasone treatment (10 nM, 48 h) reduced maximum responses of cyclic AMP formation induced by 5-HT and 5-carboxamidotryptamine without alterations in the EC50 value. In contrast, treatment with the mineralocorticoid aldosterone (48 h) had no significant effects on 5-HT-induced cyclic AMP formation with concentrations up to 10 nM. It was observed that dexamethasone treatment (1-100 nM, 3-72 h) also decreased the expression of 5-HT7 receptor mRNA, using reverse transcription and polymerase chain reaction analysis. A significant reduction in expression of 5-HT7 mRNA appeared at 3 h of dexamethasone treatment and reached a maximum at 6 h of treatment. On the other hand, dexamethasone treatment (10 nM, 48 h) did not affect basal levels of cyclic AMP and cyclic AMP synthesis stimulated by isopr...Continue Reading

Citations

Aug 24, 1999·Journal of Cerebral Blood Flow and Metabolism : Official Journal of the International Society of Cerebral Blood Flow and Metabolism·Z CohenE Hamel
Jul 13, 2000·Journal of Psychopharmacology·F Chaouloff
May 9, 2000·Journal of Neurochemistry·A García-OstaJ Del Río
Oct 3, 1999·Physiological Reviews·A J Morris, C C Malbon
Oct 4, 2019·European Journal of Medicinal Chemistry·Sangeetha-Laura ThirumaranChristophe Rochais
Oct 27, 2006·European Journal of Pharmacology·Benita SjögrenPer Svenningsson

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