1. Adenosine and the A1-adenosine receptor agonist R-PIA, exerted a negative inotropic effect in isolated, electrically driven left atria of wild-type mice. 2. In left atria of mice overexpressing the A1-adenosine receptor, adenosine and R-PIA exerted a positive inotropic effect. 3. The positive inotropic effect of adenosine and R-PIA in transgenic atria could be blocked by the A1-adenosine receptor antagonist DPCPX. 4. In the presence of isoprenaline, adenosine exerted a negative inotropic effect in wild-type atria but a positive inotropic effect in atria from A1-adenosine receptor overexpressing mice. 5. The rate of beating in right atria was lower in mice overexpressing A1-adenosine receptors compared with wild-type. 6. Adenosine exerted comparable negative chronotropic effects in right atria from both A1-adenosine receptor overexpressing and wild-type mice. 7. A1-adenosine receptor overexpression in the mouse heart can reverse the inotropic but not the chronotropic effects of adenosine, implying different receptor-effector coupling mechanisms.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1571796 | PMC |
| http://dx.doi.org/10.1038/sj.bjp.0702963 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The ex vivo effects of hypoxanthine-tricyclano, a synthetic adenosine analogue, on rat left and right atria.
Gen Physiol Biophys
November 2024
Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
Hypoxanthine-tricyclano is a synthetic adenosine analogue, in which adenine and ribose have been replaced by hypoxanthine and a morpholino-derived tricyclic moiety, respectively. We investigated whether hypoxanthine-tricyclano could influence atrial inotropy and/or chronotropy, two important functions regulated by the A1 receptor, the main adenosine receptor type of the supraventricular myocardium. Paced left atria and spontaneously beating right atria, isolated from male, 30-35 weeks old, Wistar rats, were used.
View Article and Find Full Text PDFPutative Role of Adenosine A1 Receptors in Exogenous Ketone Supplements-Evoked Anti-Epileptic Effect.
Int J Mol Sci
September 2024
Ketone Technologies LLC., Tampa, FL 33612, USA.
Approximately 30% of patients with epilepsy are drug-refractory. There is an urgent need to elucidate the exact pathophysiology of different types of epilepsies and the mechanisms of action of both antiseizure medication and metabolic therapies to treat patients more effectively and safely. For example, it has been demonstrated that exogenous ketone supplement (EKS)-generated therapeutic ketosis, as a metabolic therapy, may decrease epileptic activity in both animal models and humans, but its exact mechanism of action is unknown.
View Article and Find Full Text PDFPharmacology of Adenosine A Receptor Agonist in a Humanized Esterase Mouse Seizure Model Following Soman Intoxication.
Neurotox Res
September 2024
Neuroscience Department, Medical Toxicology Research Division, U.S. Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD, 21010-5400, USA.
Recently a novel genetically modified mouse strain with serum carboxylesterase knocked-out and the human acetylcholinesterase gene knocked-in (KIKO) was created to simulate human responses to nerve agent (NA) exposure and its standard medical treatment. A adenosine receptor (AAR) agonist N-bicyclo-(2.2.
View Article and Find Full Text PDFAdenosine triggers early astrocyte reactivity that provokes microglial responses and drives the pathogenesis of sepsis-associated encephalopathy in mice.
Nat Commun
July 2024
Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, 66421, Homburg, Germany.
Article Synopsis
- Scientists studied how inflammation in the body can affect the brain in mice, especially when they gave the mice a substance called LPS.* -
- They found that a chemical called adenosine increased quickly, causing certain brain cells (astrocytes) to become active and promote inflammation.* -
- When they blocked the action of adenosine in these astrocytes, it helped reduce inflammation and improve the mice's brain functions and mood, suggesting that targeting this process could help treat related conditions.*
Activating A1 adenosine receptor signaling boosts early pulmonary neutrophil recruitment in aged mice in response to Streptococcus pneumoniae infection.
Immun Ageing
June 2024
Department of Microbiology and Immunology, School of Medicine, University at Buffalo, Buffalo, NY, USA.
Background: Streptococcus pneumoniae (pneumococcus) is a leading cause of pneumonia in older adults. Successful control of pneumococci requires robust pulmonary neutrophil influx early in infection. However, aging is associated with aberrant neutrophil recruitment and the mechanisms behind that are not understood.
View Article and Find Full Text PDFWant 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!