Aims: To investigate whether ascorbic acid (AA) can influence endothelium-dependent relaxation by modulating the spread of endothelial hyperpolarization through the arterial wall via gap junctions.
Methods: Force development and membrane potential were monitored by myography and sharp electrode techniques in isolated rabbit iliac arteries.
Results: AA prevented the ability of the gap junction blocker 2-aminoethoxydiphenyl borate to inhibit endothelium-dependent relaxations and subintimal smooth muscle hyperpolarizations evoked by cyclopiazonic acid in the presence of nitric oxide (NO) synthase and cyclooxygenase blockade. AA also prevented the ability of a connexin-mimetic peptide targeted against Cx37 and Cx40 (37,40Gap 26) to attenuate the transmission of endothelial hyperpolarization to subintimal smooth muscle, and a peptide targeted against Cx43 (43Gap 26) to attenuate the spread of subintimal hyperpolarization to subadventitial smooth muscle and the associated mechanical relaxation. Parallel studies with endothelium-denuded preparations demonstrated that AA and cyclopiazonic acid both depressed relaxation evoked by the NO donor MAHMA NONOate.
Conclusions: The data suggest that AA can modulate arterial function through a previously unrecognized ability to preserve electrotonic signalling via myoendothelial and homocellular smooth muscle gap junctions under conditions where cell coupling is depressed. Underlying mechanisms do not involve amplification of 'residual' NO activity by AA.
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http://dx.doi.org/10.1159/000104254 | DOI Listing |
Exp Physiol
January 2025
Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia.
The mechanisms linking maternal asthma (MA) exposure in utero and subsequent risk of asthma in childhood are not fully understood. Pathological airway remodelling, including reticular basement membrane thickening, has been reported in infants and children who go on to develop asthma later in childhood. This suggests altered airway development before birth as a mechanism underlying increased risk of asthma in children exposed in utero to MA.
View Article and Find Full Text PDFInt J Gynecol Pathol
January 2025
Departments of Pathology.
The morphologic features of uterine smooth muscle tumors (USMTs) are subject to interobserver variability and are complicated by consideration of features of fumarate hydratase deficiency (FHd) and other morphologic subtypes, with difficult cases occasionally diagnosed as smooth muscle tumor of uncertain malignant potential (STUMP). We compare immunohistochemical findings and detailed morphologic analysis of 45 USMTs by 4 fellowship-trained gynecologic pathologists with comprehensive molecular analysis, focusing on FHd leiomyomas (n=15), compared to a variety of other USMTs with overlapping morphologic features, including 9 STUMPs, 8 usual-type leiomyomas (ULM), 11 apoplectic leiomyomas, and 2 leiomyomas with bizarre nuclei (LMBN). FHd leiomyomas, defined by immunohistochemical (IHC) loss of FH and/or 2SC accumulation, showed FH mutations and/or FH copy loss in all cases, with concurrent TP53 mutations in 2 tumors.
View Article and Find Full Text PDFAnal Chem
January 2025
Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
Microelectrodes offer exceptional sensitivity, rapid response, and versatility, making them ideal for real-time detection and monitoring applications. Photoelectrochemical (PEC) sensors have shown great value in many fields due to their high sensitivity, fast response, and ease of operation. Nevertheless, conventional PEC sensing relies on cumbersome external light sources and bulky electrodes, hindering its miniaturization and implantation, thereby limiting its application in real-time disease monitoring.
View Article and Find Full Text PDFRationale: Airflow obstruction refractory to β2 adrenergic receptor (β2AR) agonists is an important clinical feature of infant respiratory syncytial virus (RSV) bronchiolitis, with limited treatment options. This resistance is often linked to poor drug delivery and potential viral infection of airway smooth muscle cells (ASMCs). Whether RSV inflammation causes β2AR desensitization in infant ASMCs is unknown.
View Article and Find Full Text PDFFront Pharmacol
January 2025
Respiratory Department II, National Clinical Research Center for Respiratory Diseases, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China.
Multisystemic smooth muscle dysfunction syndrome (MSMDS) is an autosomal dominant disorder caused by mutations in the gene, resulting in variable clinical manifestation and multi-organ dysfunction. Interstitial lung disease (ILD) is a rare phenotype of this condition. We describe a rare infant case of an 8-month-old boy who presented with progressively worsening dyspnea, along with intermittent episodes of respiratory distress and cyanosis since birth.
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