Myocardial Reperfusion Injury/metabolism; Myocardium/metabolism; Receptors, G-Protein-Coupled/metabolism; Signal Transduction/physiology; Adrenergic beta-Agonists/pharmacology; Animals; Blotting, Western; Cells, Cultured; G-Protein-Coupled Receptor Kinase 2/genetics; G-Protein-Coupled Receptor Kinase 2/metabolism; Heart/drug effects; Heart/physiopathology; Isoproterenol/pharmacology; Mice; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Knockout; Mice, Transgenic; Myocardial Reperfusion Injury/genetics; Myocardial Reperfusion Injury/physiopathology; Myocardium/pathology; Nitric Oxide/metabolism; Nitric Oxide Donors/pharmacology; Nitric Oxide Synthase Type III/genetics; Nitric Oxide Synthase Type III/metabolism; Rats; Receptors, Adrenergic, beta/genetics; Receptors, Adrenergic, beta/metabolism; Receptors, Adrenergic, beta-1/genetics; Receptors, Adrenergic, beta-1/metabolism; Receptors, G-Protein-Coupled/genetics; Reverse Transcriptase Polymerase Chain Reaction; S-Nitrosoglutathione/pharmacology; S-Nitrosothiols/metabolism; Signal Transduction/drug effects; Signal Transduction/genetics