ArticleBritish journal of pharmacology2001
Changes in extracellular pH and myocardial ischaemia alter the cardiac effects of diadenosine tetraphosphate and pentaphosphate.
Article in British journal of pharmacology, 2001. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
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Who cites it
3 citing papers in PubMed, 10 citations in OpenAlex.
- The effects of norepinephrine in shockable cardiac arrest, a scoping review.Scandinavian journal of trauma, resuscitation and emergency medicine · 2025Article
- Fabrication and Characterization of Drug-Loaded Conductive Poly(glycerol sebacate)/Nanoparticle-Based Composite Patch for Myocardial Infarction Applications.ACS applied materials & interfaces · 2020Article
- Diadenosine-5-phosphate exerts A1-receptor-mediated proarrhythmic effects in rabbit atrial myocardium.British journal of pharmacology · 2003Article
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Authors and funding
3 authors at 1 institution in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
1. The structural conformation of diadenosine tetraphosphate (Ap(4)A) and pentaphosphate (Ap(5)A) has been reported to alter as pH is reduced. As such, it is possible that the cardiac effects of Ap(4)A and Ap(5)A vary during acidosis and myocardial ischaemia due to changes in ligand structure, receptor proteins or intracellular signalling. 2. We investigated whether the cardiac electrophysiological and coronary vasomotor effects of Ap(4)A and Ap(5)A are preserved under conditions of extracellular acidosis (pH 6.5) and alkalosis (pH 8.5) and whether Ap(4)A has any electrophysiological or antiarrhythmic effects during ischaemia. 3. Transmembrane right ventricular action potentials, refractory periods and coronary perfusion pressure were recorded from isolated, Langendorff-perfused guinea-pig hearts under constant flow conditions. The effects of 1 nM and 1 microM Ap(4)A and Ap(5)A were studied at pH 7.4, 6.5 and 8.5. The effects of 1 microM Ap(4)A were studied during global low-flow ischaemia and reperfusion. 4. At pH 7.4, Ap(4)A and Ap(5)A increased action potential duration (APD(95)) and refractory period (RP) and reduced coronary perfusion pressure. The electrophysiological effects were absent at pH 6.5 while the reductions in perfusion pressure were attenuated. At pH 8.5, Ap(4)A increased RP but the effects of Ap(4)A and Ap(5)A on perfusion pressure were attenuated. During ischaemia, Ap(4)A had no antiarrhythmic or electrophysiological effects. 5. These data demonstrate the importance of extracellular pH in influencing the effects of Ap(4)A and Ap(5)A on the heart and indicate that any potentially cardioprotective effects of these compounds during normal perfusion at physiological pH are absent during ischaemia.
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