Following the monographs by STRAUB (1924) and LENDLE (1935), this is the third contribution to the "Pharmacology of Cardiac Glycosides" within the Handbook of Experimental Pharmacology, which was founded by ARTHUR HEFFTER and con­ tinued by WOLFGANG HEUBNER. Because of the need created by the length of time that had elapsed since LENDLE'S work, the editorial board requested the rapid ap­ pearance of this 56th volume, which represents current knowledge of the pharma­ cology and clinical pharmacology of cardiac glycosides. In order to avoid any delay, numerous authors were invited to contribute because shorter contributions take less time to prepare and are consequently more up-to-date. The disadvantage is that some overlap between certain chapters could not be avoided, despite the editor's efforts. Overlapping can, however, actually be useful, in that differing opinions may be provided and topical issues discussed from varying viewpoints. This re­ minds the reader that scientific horizons in medicine should often be widened or revised. I would like to thank DR. ALANNA Fox and DR. K. ANANTHARAMAN for their help and advice in the revision of certain chapters. I am also grateful to Springer­ Verlag, and particularly to MR. WINSTANLEY and MR. EMERSON, for their contribu­ tion to the completion of this volume through translation and corrections. In con­ clusion I would like to thank MRS. WALKER, MR. BISCHOFF, MRS. SEEKER, and MR. BERGSTEDT of Springer-Verlag for their helpful support.

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1 Introduction and Remarks on the History of Cardiac Glycosides.- 2 Chemistry and Structure-Activity Relationships of Cardioactive Steroids.- A. Introduction.- B. Structure-Activity Relationships.- I. Uncertainties in Structure-Activity Relationships.- II. 3?-OH Group.- III. A-B Connection.- IV. C-D Connection.- V. Structure at C14 and C15.- VI. Side-Chain.- C. Influence of Additional Structural Modifications.- I. Halogens.- II. Branching at C3.- III. N-Analogs.- IV. Structure at C16.- V. Other Compounds.- D. Summary.- References.- Methods for the Determination of Cardiac Glycosides.- 3 Chemical and Chromatographic Methods.- A. Introduction.- B. Spectroscopic Procedures.- I Alkaline Reagents.- II. Acidic Reagents.- III. Fluorescence Spectroscopy.- IV. Quantitative Determination After Chromatography.- V. Quantitative Determination in Biologic Material.- C. Chromatographic Procedures.- I. Paper Chromatography and Thin Layer Chromatography.- II. Gas Chromatography.- III. Liquid Chromatography.- References.- 4 Use of Radioactively Labeled Glycosides.- A. Introduction.- B. Prerequisites for the Use of Isotope Techniques.- C. Production of Radioisotope Labeled Glycosides.- I. Biosynthesis.- II. Wilzbach Labeling.- III. Catalytic Exchange with Tritium Water.- IV. Reductive Tritiation.- V. Partial Synthetic Procedures.- D. Stability of the Radioactive Label.- E. Purity Testing of Labeled Glycosides.- F. Pharmacokinetic Investigations with Labeled Cardiac Glycosides.- G. Pharmacologic Investigations in Humans.- References.- 5 Radioimmunologic Methods.- A. Radioimmunoassay.- I. Basic Principles.- II. Antibodies.- 1. Immunogens and Immunization.- 2. Characterization.- III. Tracers.- 1. General Remarks.- 2. Conjugates for Labeling with 125I.- 3. Iodination.- IV. Standards.- V. Separation Methods.- VI. Assay Performances.- VII. Automation.- B. Enzyme Immunoassay.- I. Introduction.- II. Heterogeneous Enzyme Immunoassay.- III. Homogeneous Enzyme Immunoassay.- References.- 6 ATPase for the Determination of Cardiac Glycosides.- A. Introduction.- B. Preparation of ATPase.- C. Extraction Procedure from Biological Fluids.- D. Determination Based on Measurement of Enzyme Activity.- I. Measurement of the Hydrolysis of ATP.- II Inhibition of ATPase by Different Cardiac Glycosides.- III. Precision and Sensitivity of the Assay.- IV. Comparison of Results Obtained by ATPase Activity and Radioimmunoassay.- E. Determination Based on Isotope Displacement.- I. Binding Affinities of Different Cardiac Glycosides.- II. Precision and Sensitivity of the Assay.- III. Comparison of Results Obtained by Isotope Displacement and Other Assays.- F. Commentary.- I. Preparation of ATPase.- 1. ATPase Activity Assay.- 2. Isotope Displacement Assay.- II. Extraction Procedure.- 1. Dichlormethane.- 2. Chloroform.- III. Assay Procedure.- 1. ATPase Activity Assay.- 2. Isotope Displacement Assay.- References.- 7 Rubidium Uptake in Erythrocytes.- A. Introduction and Principle of the Method.- B. Factors Affecting the 86Rb Uptake of Human Erythrocytes.- I. Measurement of 86Rb-Activity.- II. Influences from Incubation Medium, Ion Concentrations, and pH.- 1. Influence of Rb+ Concentration and Specific Activity.- 2. Influence of Sodium Concentration.- 3. Influence of Calcium and Magnesium Concentration.- 4. Influence of pH During Incubation.- III. Influence of the Erythrocyte Preparation.- 1. Concentration of Erythrocytes in the Incubation Medium.- 2. Age of the Erythrocyte Preparation.- 3. Source of Erythrocyte Samples.- IV. Influence of Incubation Procedures on the 86REA.- 1. Incubation Temperature.- 2. Time of Incubation of Erythrocytes with 86Rb+.- 3. Influence of Preincubation of Erythrocytes with Digitalis.- V. Separation of Erythrocytes from Incubation Medium After Incubation.- C. Influence of Various Cardiac Glycosides, Genins, and Conjugates on the 86REA.- D. Specificity of the Inhibition of 86Rb Uptake.- I. Diverse Drugs.- II. Spironolactone.- III. Human Plasma.- E. Correlation of Activity of Cardiac Glycosides in 86REA and Cardioactivity.- F. Use of 86REA for Measurement in Body Fluids.- I. Plasma Glycoside Concentrations.- 1. Extraction Procedure.- 2. Preparation of the Extract.- 3. Preparation of Erythrocytes.- 4. Incubation Assay.- 5. Standard Curves.- 6. Calculation.- II. Glycoside Concentrations in Different Biological Media.- G. Comparison of Plasma Glycoside Measurements Using 86REA and Immunochemical Methods.- I. Determination of Plasma Digoxin.- II. Determination of Plasma Digitoxin.- H. Criticism of the Method as Used for Serum and Tissue Glycoside Concentration Determination.- I. Extraction.- II. Plasma Volume.- III. Biological Standard.- IV. Various Cardiac Glycosides.- V. Range of Discrimination.- VI. Use of the Method.- VII. Precision and Accuracy.- J. Plasma Concentrations of Cardiac Glycosides.- References.- Biological Methods for the Evaluation of Cardiac Glycosides.- 8 Evaluation of Cardiac Glycosides in the Intact Animal.- A. Introduction.- B. Toxicity as a Parameter of Biologic Efficacy.- I. Determination of the Lethal Dose in Anesthetized Animals by Intravenous Infusion Continued Until Cardiac Arrest.- 1. Cats.- 2. Guinea Pigs.- 3. Dogs.- 4. Pigs.- II. Determination of the Lethal Dose in Unanesthetized Animals.- 1. Frogs.- 2. Pigeons.- 3. Mice and Rats.- III. Factors Which Modify Toxicity.- 1. Anesthesia.- 2. Hypothermia.- 3. Hypoxia.- 4. Acidosis.- 5. Alkalosis.- 6. Age.- 7. Seasons.- 8. Autonomic Tone.- C. Sublethal Parameters of the Efficacy of Cardiac Glycosides.- I. The Inotropic Effect.- II. The Arrhythmogenic Effect.- III. The Kaliuretic Effect.- IV. Subacute Poisoning.- D. Determination of the Therapeutic Range.- I. Arrhythmogenic Dose and Lethal Dose.- II. Inotropic Dose and Lethal Dose.- III. Experimental Cardiac Failure.- E. Intestinal Absorption.- I. Comparison of Oral with Intravenous or Subcutaneous Efficacy in Unanesthetized Animals.- 1. By Determining the Lethal Dose.- 2. By Demonstrating ECG Changes.- 3. By Determining the Kaliuretic Effect in Rats.- 4. Tolerance Test with Acetylstrophanthidin After Oral Pretreatment.- II. Comparison of the Lethal Dose or Arrhythmogenic Dose by Intraduodenal and Intravenous Infusion in Anesthetized Animals.- III. Oral or Intraduodenal Pretreatment Followed by Determination of the Supplementary Dose in Anesthetized Animals.- IV. Determination of the Residue After Intraduodenal Administration.- V. Determination of Intestinal Abs…