The serotonin (5-hydroxtryptamine, 5-HT) transporter (SERT) plays a critical role in the inactivation of synaptic 5-HT and has been implicated in multiple psychiatric and peripheral disorders. SERT regulation studies demonstrate that activation of cyclic guanosine monophosphate (cGMP)/protein kinase G (PKG)-linked pathways can increase SERT activity. As cGMP actions are limited by cGMP-specific phosphodiesterase (PDEs), we investigated whether the cGMP-specific PDE5 inhibitor sildenafil (Viagra) can stimulate 5-HT uptake and potentiate cGMP-mediated regulation. In RBL-2H3 cells, SERT activity was stimulated by sildenafil in a concentration- and time-dependent manner. Sildenafil also enhanced the stimulation of SERT triggered by the adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA), effects blocked by the PKG inhibitor N-[2-(methylamino)ethy]-5-isoquinoline-sulfonamide (H8). Sildenafil stimulation of 5-HT uptake arises from an increase in 5-HT transport Vmax and is paralleled by elevated SERT surface antagonist binding, also H8-sensitive. These findings implicate cGMP-targeted PDEs in limiting the regulation of antidepressant-sensitive 5-HT transport.
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http://dx.doi.org/10.1016/j.ejphar.2004.09.023 | DOI Listing |
J Cereb Blood Flow Metab
January 2025
Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Pontypridd, UK.
To what extent sildenafil, a selective inhibitor of the type-5 phosphodiesterase modulates systemic redox status and cerebrovascular function during acute exposure to hypoxia remains unknown. To address this, 12 healthy males (aged 24 ± 3 y) participated in a randomized, placebo-controlled crossover study involving exposure to both normoxia and acute (60 min) hypoxia (Fi = 0.14), followed by oral administration of 50 mg sildenafil and placebo (double-blinded).
View Article and Find Full Text PDFEClinicalMedicine
February 2025
Human Stem Cell and Genome Engineering Center, University of California Los Angeles David Geffen School of Medicine, UCLA - CHS 36 - 125/133/143 650 Charles E. Young Dr. South, Los Angeles, CA, 90095, USA.
Background: Phosphodiesterase 5 (PDE5) inhibitors, owing to their mechanism of action, have been gaining recognition as a potential case of drug repurposing and combination therapy for diabetes treatment. We aimed to examine the effect of long and short half-life PDE5 inhibitors have on Haemoglobin A1c (HbA1c) levels.
Methods: A systematic review and meta-analysis was conducted of randomised controlled trials (RCTs) in people with elevated HbA1c (>6%) to assess mean difference in HbA1c levels from baseline versus controls after any PDE5 inhibitor intervention of ≥4 weeks, excluding multiple interventions.
Cureus
December 2024
Optometric - Glaucoma, Leicester Royal Infirmary, Leicester, GBR.
Colour vision defects (CVDs) can be both congenital and acquired, with acquired dyschromatopsia often associated with medication toxicity. This review explores various standardised colour vision tests used to detect these defects, including the Ishihara plate test, Farnsworth-Munsell 100 hue test, and anomaloscopes. These methods are evaluated for their effectiveness in diagnosing CVDs, particularly in acquired conditions.
View Article and Find Full Text PDFMedicine (Baltimore)
January 2025
Division of Hematology/Oncology, Changhua Christian Hospital, Changhua, Taiwan.
Rationale: Chylothorax is a rare adverse effect that is associated with dasatinib, a tyrosine kinase inhibitor administered for chronic myeloid leukemia (CML) treatment. Most reported cases have described standard dosing. In this case report, we described a 43-year-old male patient with CML who developed chylothorax after 4 years of low-dose dasatinib therapy.
View Article and Find Full Text PDFCommun Biol
January 2025
Department of General Surgery & Guangdong Provincial Key Laboratory of Precision Medicine for Gastrointestinal Tumor, Nanfang Hospital, Southern Medical University, Guangzhou, China.
Phosphodiesterase-5 (PDE5) inhibitors have shown promise as anti-cancer agents in malignancies. However, their specific effects on gastric cancer (GC) and the underlying mechanisms remain elusive. Our aim was to investigate this by combining evidence from population-based studies with data obtained from in vivo and in vitro experiments.
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