An intron-containing gene encoding a novel human serotonin (5-HT) receptor was isolated from human genomic and cDNA libraries with probes directed to transmembrane regions of the adenylate cyclase stimulatory Drosophila serotonin receptor gene, 5-HTdrol. Membranes harvested from transiently transfected Cos-7 cells displayed high affinity (Kd = 8.5 nM), saturable (Bmax = 6.6 pmol/mg protein) [3H]5-HT binding. The rank order of potencies for serotonergic ligands to displace specific [3H]5-HT binding was: 5-carboxamido-tryptamine > methiothepin > metergoline > 5-HT > 8-hydroxy-2-(di-n-propylamino)tetralin > sumatriptan > ketanserin > zacopride. 5-HT produced a dose-dependent (EC50 = 992 nM) stimulation (approximately 20-fold) of cAMP accumulation in transiently transfected cells, and this response was antagonized by the nonselective 5-HT antagonist methiothepin. RNA for this gene was predominantly detected in the human brain and a subset of peripheral tissues including coronary artery and several tissues of the gastrointestinal tract. The molecular biological and pharmacological properties of this receptor suggest that it is the first member of a new serotonin receptor subfamily (5-HT7). The second messenger coupling, and tissue distribution indicate a possible identity to 5-HT receptors that mediate relaxant responses in certain isolated blood vessels.
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J Microbiol Biotechnol
November 2024
Department of Biotechnology and Department of Integrative Food, Bioscience and Biotechnology (BK21 FOUR), Chonnam National University, Gwangju 61186, Republic of Korea.
This study investigates the modulatory effects of nicergoline, a major bioactive compound derived from ergot fungus, on the 5-hydroxytryptamine 3A (5-HT3A) receptor. Utilizing a two-electrode voltage-clamp technique, we evaluated the impact of nicergoline on the 5-HT-induced inward current (I) in 5-HT3A receptors. Our findings reveal that nicergoline inhibits I in a reversible and concentration-dependent manner.
View Article and Find Full Text PDFExp Neurol
January 2025
Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China. Electronic address:
Depression is one of the most common non-motor symptoms in Parkinson's disease (PD) and the hyperactivity of the lateral habenula (LHb) may contribute to depression. The present study was performed to investigate the effects and mechanisms of group I metabotropic glutamate receptors (mGluRs) in the LHb on PD-related depressive-like behaviors. Unilateral 6-hydroxydopamine lesions of the substantia nigra pars compacta (SNc) were used to establish the PD rat model.
View Article and Find Full Text PDFBiochim Biophys Acta Mol Basis Dis
January 2025
National Forensic Sciences University, Gandhinagar 382007, Gujarat, India. Electronic address:
Cancer-associated cachexia (CAC) is a debilitating condition, observed in patients with advanced stages of cancer. It is marked by ongoing weight loss, weakness, and nutritional impairment. Lower tolerance of chemotherapeutic agents and radiation therapy makes it difficult to treat CAC.
View Article and Find Full Text PDFACS Chem Neurosci
January 2025
Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100 Copenhagen, Denmark.
The serotonin 7 receptor (5-HTR) regulates various processes in the central nervous system, including mood, learning, and circadian rhythm control, among others. Receptor activation can lead to activation of the Gα protein and a subsequent increase of intracellular cyclic adenosine monophosphate (cAMP). Receptor interaction with inverse agonists results in a decrease of basal cAMP levels and therefore a downstream effect of reduced neuronal excitability and neurotransmission.
View Article and Find Full Text PDFAnn Med
December 2025
Department of Hepatobiliary and Pancreatic Surgery, Ningbo Medical Center Lihuili Hospital, Ningbo, Zhejiang, China.
Background: Numerous meta-analyses have identified various risk factors for hepatocellular carcinoma (HCC), prompting a comprehensive study to synthesize evidence quality and strength.
Methods: This umbrella review of meta-analyses was conducted throughout PubMed, EMBASE, Web of Science, and Cochrane Database of Systematic Reviews. Evidence strength was evaluated according to the evidence categories criteria.
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