Heart Ventricles/metabolism; Myocytes, Cardiac/metabolism; Platelet Activating Factor/metabolism; Sodium-Hydrogen Exchangers/metabolism; Sodium/metabolism; Acidosis/metabolism; Alkalosis/metabolism; Animals; Azepines/pharmacology; Benzophenanthridines/pharmacology; Dose-Response Relationship, Drug; Flavonoids/pharmacology; Guanidines/pharmacology; Guinea Pigs; Heart Ventricles/drug effects; Hydrogen-Ion Concentration; Indoles/pharmacology; Ion Transport; Maleimides/pharmacology; Mitogen-Activated Protein Kinase Kinases/antagonists & inhibitors; Mitogen-Activated Protein Kinase Kinases/metabolism; Myocytes, Cardiac/drug effects; Phospholipid Ethers/pharmacology; Platelet Membrane Glycoproteins/drug effects; Platelet Membrane Glycoproteins/metabolism; Protein Kinase C/antagonists & inhibitors; Protein Kinase C/metabolism; Protein Kinase Inhibitors/pharmacology; Receptors, G-Protein-Coupled/drug effects; Receptors, G-Protein-Coupled/metabolism; Signal Transduction; Sodium-Hydrogen Exchangers/antagonists & inhibitors; Spectrometry, Fluorescence; Sulfones/pharmacology; Time Factors; Triazoles/pharmacology