Cardioprotection subtypes

Palmer TM, Stiles GL (2000) Identification of threonine residues controlling the agonist-dependent phosphorylation and desensitization of the rat A3 adenosine receptor. Mol Pharmacol 57 539-545 Parsons M, Young L, Lee JE, Jacobson KA, Liang BT (2000) Distinct cardioprotective effects of adenosine mediated by differential coupling of receptor subtypes to phospholipases C and D. FASEB J 14 1423-1431... 

Rose Meyer RB, Hope W (1990) Evidence that A2 purinoceptors are involved in endothelium-dependent relaxation of the rat thoracic aorta. Br J Pharmacol 100(3) 576-580 Rubio R, Ceballos G (2003) Sole activation of three luminal adenosine receptor subtypes in different parts of coronary vasculature. Am J Physiol 284(1) H204-H214 Safran N, Shneyvays V, Balas N, Jacobson KA, Nawrath H, Shainberg A (2001) Cardioprotective effects of adenosine A3 and A3 receptor activation during hypoxia in isolated rat cardiac myocytes. Mol Cell Biochem 217(1-2) 143-152 Salvatore CA, Tilley SL, Latour AM, Fletcher DS, Roller BH, Jacobson MA (2000) Disruption of the A3 adenosine receptor gene in mice and its effect on stimulated inflammatory cells. J Biol Chem 275(6) 4429-4434... 

EVIDENCE FOR A DELTA OPIOID RECEPTOR SUBTYPE BEING RESPONSIBLE FOR OPIOID-INDUCED CARDIOPROTECTION... 

Adenosine binds to adenosine receptors (AD-Rs) (subtypes Ah A2A, A2b and A3). Ap and Ap R activation gives Gai-mediated inhibition of adenylyl cyclase (resulting in decreased cAMP) and Gai/Gao-mediated activation of a K+ channel (with a de-excitatory hyperpolarizing effect). A2A and A2B activation gives Gas-mediated stimulation of adenylate cyclase (resulting in elevated cAMP). Adenosine acting via particular receptors variously has cardioprotective, neuroprotective, sedative, anticonvulsant, soporific, vasodilatory and bronchoconstrictive effects. The plant-derived methylxanthines theophylline and caffeine are adenosine A1 and A2 receptor antagonists (Table 5.1). 

BQ 123 is a cyclic pentapeptide, which acts as a subtype-selective (ETa) endothelin receptor antagonist. It shows cardioprotective effects in an animal model of nryocardial infarction. It is used as a pharmacological tool. 

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