21. Aminophylline is a nonselective adenosine receptor antagonist and phosphodiesterase inhibitor. 22. Adenosine is an endogenous extracellular messenger that can regulate myocardial oxygen needs.23. With respect to breathing, caffeine acts as a competitive adenosine antagonist. 24. Adenosine inhibits respiratory drive by blocking the electrical activity of respiratory neurons.25. They release Adenosine triphosphate ( ATP ), which activate purinergic receptors. 26. In one report, PIMT was inhibited by adenosine dialdehyde. 27. This protein is associated with adenosine triphosphatases ( ATPases ). 28. This gene encodes adenosine kinase, an abundant enzyme in mammalian tissues. 29. There are currently four types of adenosine receptors found in the heart. 30. The other three adenosine receptors are involved in bone formation.
