1. Ketanserin may influence baroreflex function by blocking 5-HT(2A) receptors and/or alpha(1)-adrenoceptors through central and/or peripheral mechanisms. 2. In the present study, we tested the hypothesis that the baroreflex sensitivity (BRS)-enhancing effects of ketanserin are mediated by central 5-HT(2A) receptors in spontaneously hypertensive rats (SHR). 3. Using a conjugate of a monoclonal antibody to the serotonin reuptake transporter (SERT) and the toxin saporin (anti-SERT-SAP), which specifically eliminates the neurons that express SERT, the effects of ketanserin (0.3 and 3.0 mg/kg, i.g.) on BRS, blood pressure (BP), heart period (HP) and blood pressure variability (BPV) were compared between conscious intact SHR and SHR pretreated with anti-SERT-SAP. 4. Immunochemistry showed that, 2 weeks after intracerebroventricular injection of the toxin, 5-HT expression was strikingly attenuated in the brain, whereas values of BRS, BPV and BP were similar to those in the sham group. In intact SHR, 0.3 mg/kg ketanserin significantly improved BRS (191% control) and reduced BPV without affecting BP; at 3.0 mg/kg, ketanserin significantly increased BRS (197% control) and decreased BPV and BP. In toxin-pretreated SHR, only the high dose of ketanserin improved BRS (132% control), neither of the ketanserin doses reduced BPV, but both significantly decreased BP. 5. We conclude that the BRS-enhancing effects of ketanserin are mediated largely by central 5-HT(2A) receptors, whereas the antihypertensive effect of ketanserin persists even after destruction of serotonergic neurons in the central nervous system.
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http://dx.doi.org/10.1111/j.1440-1681.2007.04626.x | DOI Listing |
Int J Mol Sci
December 2024
Neuroscience Research Institute, Gachon University, Incheon 21565, Republic of Korea.
To elucidate the potential roles of presynaptic and postsynaptic serotonergic activity in impulsivity traits, we investigated the relationship between self-reported impulsiveness and serotonin transporter (5-HTT) and 5-HT2A receptors in healthy individuals. In this study, 26 participants completed 3-Tesla magnetic resonance imaging and positron emission tomography with [C]DASB and [C]MDL100907. To quantify 5-HTT and 5-HT2A receptor availability, the binding potential (BP) of [C]DASB and [C]MDL100907 was derived using the simplified reference tissue model with cerebellar gray matter as the reference region.
View Article and Find Full Text PDFNeuropsychiatr Dis Treat
December 2024
Department of Medicine and Surgery, Kore University of Enna, Enna (EN), Italy.
Arch Razi Inst
June 2024
Medical Plants Research Center, Basic Health Sciences Institute, Shahrekord University of Medical Sciences, Shahrekord, Iran.
In the present study, the mechanisms involved in scopolamine-induced memory impairment have been investigated. The molecular events that take place during memory mostly include mechanisms that are seen in the acquisition phase. Results showed that one of the mechanisms of memory destruction caused by scopolamine, in addition to weakening the cholinergic system, is the indirect effect of scopolamine on other neurotransmitter systems, including the glutamatergic system.
View Article and Find Full Text PDFBrain Res
December 2024
Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen 2100, Denmark. Electronic address:
Psychedelics show promise in treating psychiatric disorders. Therapeutic effects appear to involve activation of the 5-Hydroxytryptamine 2A receptor (5-HTR), a G protein-coupled receptor (GPCR). Several SNPs of the 5-HTR naturally occur, which are associated with differences in receptor function and altered responsiveness to treatments.
View Article and Find Full Text PDFAnn Med
December 2025
Department of Anatomy, College of Medicine, King Khalid University, Abha, Saudi Arabia.
Background: Substance use disorders are multifaceted conditions influenced by both genetic and environmental factors. Serotonergic pathways are known to be involved in substance use disorder susceptibility, with genetic markers within serotonin receptor genes identified as potential risk factors.
Methods: To further explore this relationship, we conducted a study to investigate the association between several polymorphisms in five serotonin receptor genes (, , ) and substance use disorders (SUD) in Jordanian males by sequencing genotypes in 496 SUD patients and 496 healthy controls.
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