Objectives: Nitric oxide, a neurotransmitter in the noncholinergic, nonadrenergic nervous system, is a mediator of relaxation of GI smooth muscle and of visceral nociception mainly studied in vitro. Sildenafil stimulates the nitric oxide guanosine 3', 5'-cyclic monophosphate (NO-cGMP) pathway through inhibition of phosphodiesterase 5. The aims of this study were to evaluate in vivo the effect of stimulation of the NO-cGMP pathway on rectal tone, distensibility, and perception in healthy individuals and in patients with irritable bowel syndrome (IBS).
Methods: In eight healthy subjects and four patients with IBS rectal tone, distensibility and perception thresholds were measured with an electronic barostat both before and 60 min after administration of sildenafil (50 mg p.o.). Perception was scored on a graded scale of 0-6. At the end of a distension series an anatomic questionnaire was filled out by the subjects.
Results: Sildenafil significantly reduced rectal tone in healthy subjects (intrabag volume predrug: 145.5 +/- 18.7 ml vs postdrug: 164.4 +/- 16.9 ml, p = 0.01) and IBS (111.3 +/- 25.2 ml vs 136.5 +/- 33.3 ml; p = 0.01) but did not alter rectal compliance (healthy subjects: 5.8 +/- 0.4 vs 6.3 +/- 0.6 ml/mm Hg, p > 0.05; IBS subjects: 6.1 +/- 0.6 vs 7.1 +/- 1.0 ml/mm Hg, p > 0.05). Intrabag pressure and rectal wall tension to reach perception thresholds for initial sensation, sensation of stool, and urgency were not altered by sildenafil. However, intrabag volumes to reach these thresholds were significantly increased by sildenafil both in healthy subjects and in patients with IBS. Viscerosomatic referral was unchanged.
Conclusions: Stimulation of the NO-cGMP pathway decreases rectal tone but does not influence rectal distensibility. Relaxation of the rectum is accompanied by an increase in rectal volumes to reach perception thresholds in healthy subjects and in patients with IBS, but no direct effect on rectal perception can be demonstrated.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1111/j.1572-0241.2003.07661.x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Importance of neural network complexity for the automatic segmentation of individual thigh muscles in MRI images from patients with neuromuscular diseases.
MAGMA
January 2025
Aix Marseille Univ, CNRS, CRMBM, Marseille, France.
Objective: Segmentation of individual thigh muscles in MRI images is essential for monitoring neuromuscular diseases and quantifying relevant biomarkers such as fat fraction (FF). Deep learning approaches such as U-Net have demonstrated effectiveness in this field. However, the impact of reducing neural network complexity remains unexplored in the FF quantification in individual muscles.
View Article and Find Full Text PDFEvaluation of sleep disorders in children and adolescents affected by Klinefelter syndrome.
Eur J Pediatr
January 2025
Department of Maternal Infantile and Urological Sciences, Sapienza University of Rome, Rome, Italy.
Unlabelled: Klinefelter syndrome (KS) is the most common sex chromosomal aneuploidy in males (47,XXY karyotype in 80-90% of cases), primarily characterized by hypergonadotropic hypogonadism and infertility. It encompasses a broad phenotypic spectrum, leading to variability in neurocognitive and psychosocial outcomes among affected individuals. Despite the recognized correlation between KS and various neuropsychiatric conditions, studies investigating potential sleep disorders, particularly in pediatric subjects, are lacking.
View Article and Find Full Text PDFPiezo1-Induced Nasal Epithelial Barrier Dysfunction in Allergic Rhinitis.
Inflammation
January 2025
Department of Otolaryngology-Head and Neck Surgery, Shandong Provincial ENT Hospital, Shandong University, Duanxing West Road, Jinan, 250000, Shandong, China.
This study aimed to investigate the role of Piezo1 in nasal epithelial barrier dysfunction in allergic rhinitis (AR) using both in vitro and in vivo experimental methods. A total of 79 human nasal mucosal samples were collected, including 43 from AR patients and 36 from healthy controls. Additionally, 12 BALB/c mice were used for the in vivo experiments.
View Article and Find Full Text PDFImproving Understanding of Fexofenadine Pharmacokinetics to Assess Pgp Phenotypic Activity in Older Adult Patients Using Population Pharmacokinetic Modeling.
Clin Pharmacokinet
January 2025
Clinical Pharmacology and Toxicology Service, Anesthesiology, Pharmacology and Intensive Care Department, Geneva University Hospitals, 4 Rue Gabrielle Perret-Gentil, 1205, Geneva, Switzerland.
Background And Objective: Fexofenadine is commonly used as a probe substrate to assess P-glycoprotein (Pgp) activity. While its use in healthy volunteers is well documented, data in older adult and polymorbid patients are lacking. Age- and disease-related physiological changes are expected to affect the pharmacokinetics of fexofenadine.
View Article and Find Full Text PDFIL-17 as a putative hallmark of intense arthralgia and age-related serum immune mediator networks during acute chikungunya fever.
Inflamm Res
January 2025
Laboratório de Virologia Básica E Aplicada, Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais-UFMG, Belo Horizonte, MG, Brazil.
Introduction: The present study aimed at evaluating the systemic profile and network connectivity of immune mediators during acute chikungunya fever (CHIKF) according to days of symptoms onset and ageing.
Methods: A total of 161 volunteers (76 CHIKF patients and 85 non-infected healthy controls) were enrolled.
Results And Discussion: Data demonstrated that a massive and polyfunctional storm of serum immune mediators was observed in CHIKF.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!