Cyclic Nucleotides and Cardiac Contractility

摘要: The sequence of molecular events in cardiac muscle that begins with the interaction autonomic neurotransmitters their receptors and result such responses as altered contractility, rhythmicity energy metabolism are beginning to be comprehensible. There still considerable gaps knowledge, but there several working hypotheses which being subjected intense investigation. Antagonists bind specifically strongly adrenergic muscarinic will allow isolation characterization these receptors. This aspect pharmacology not discussed here. An important problem must solved is mechanism whereby receptor activation coupled initiation reactions alter contractile, ion transport metabolic responses. schemes, supported by varying amounts evidence, how mediated. messengers mediation are: Ca++ activation-contraction coupling contraction itself, cyclic AMP (adenosine 3’: 5’ — monophosphate), mediator responses, GMP (guanosine -monophosphate) cholinergic control rhythm (Fig. 1).