A Pharmacology Primer

by Kenakin

• ISBN13: 9780123705990
• ISBN10: 0123705991
• Edition: 2nd
• Format: Paperback
• Copyright: 2006-10-30
• Publisher: Elsevier Science

Summary

The First Edition of this guide was successful in assisting scientists trained in molecular biology and related fields who now need to know the basic theories, principles and practical applications of pharmacology. Pharmacology is now more relevant to the drug discovery process than ever as the genome furnishes a wealth of new targets to unravel. Pharmaceutical companies especially are finding a growing need for scientists trained in the basics of pharmacology. At GlaxoSmithKline, a pharmaceuticals world-leader, Terry Kenakin regularly teaches a course for their research scientists and has drawn on his experience to create A Pharmacology Primer.

Table of Contents

What Is Pharmacology?
About This Book	p. 1
What Is Pharmacology?	p. 1
The Receptor Concept	p. 2
Pharmacological Test Systems	p. 4
The Nature of Drug Receptors	p. 6
Pharmacological Intervention and the Therapeutic Landscape	p. 6
System-independent Drug Parameters: Affinity and Efficacy	p. 9
What Is Affinity?	p. 10
The Langmuir Adsorption Isotherm	p. 10
What Is Efficacy?	p. 13
Dose-response Curves	p. 14
Potency and Maximal Response	p. 16
p-Scales and the Representation of Potency	p. 17
Chapter Summary and Conclusions	p. 18
Derivations: Conformational Selections as a Mechanism of Efficacy	p. 18
References	p. 19
How Different Tissues Process Drug Response
Drug Response as Seen Through the "Cellular Veil"	p. 21
The Biochemical Nature of Stimulus-response Cascades	p. 23
The mathematical Approximation of Stimulus-response Mechanisms	p. 25
System Effects on Agonist Response: Full and Partial Agonists	p. 27
Differential Cellular Response to Receptor Stimulus	p. 30
Choice of Response Pathway	p. 31
Augmentation or Modulation of Stimulus Pathway	p. 31
Differences in Receptor Density	p. 31
Receptor Desensitization and Tachyphyllaxis	p. 34
The Measurement of Drug Activity	p. 34
Advantages and Disadvantages of Different Assay Formats	p. 35
Drug Concentration as an Independent Variable	p. 35
Dissimulation in Drug Concentration	p. 35
Free Concentration of Drug	p. 36
Chapter Summary and Conclusions	p. 37
Derivations	p. 38
Series Hyperbolae Can Be Modeled by a Single Hyperbolic Function	p. 38
Successive Rectangular Hyperbolic Equations Necessarily Lead to Amplification	p. 38
Saturation of Any Step in a Stimulus Cascade by Two Agonists Leads to Identical Maximal Final Responses for the Two Agonists	p. 38
Measurement of Free Drug Concentration in the Receptor Compartment	p. 39
References	p. 39
Drug-Receptor Theory
About This Chapter	p. 41
Drug-Receptor Theory	p. 42
The Use of Mathematical Models in Pharmacology	p. 42
Some Specific Uses of Models in Pharmacology	p. 43
Classical Model of Receptor Function	p. 44
The Operational Model of Receptor Function	p. 45
Two-state Theory	p. 47
The Ternary Complex Model	p. 48
The Extended Ternary Model	p. 48
Constitutive Receptor Activity	p. 49
The Cubic Ternary Complex Model	p. 50
Chapter Summary and Conclusions	p. 52
Derivations	p. 52
Radioligand Binding to Receptor Dimers Demonstrating Cooperative Behavior	p. 52
Effect of Variation in an HIV-1 Binding Model	p. 53
Derivation of the Operational Model	p. 54
Operational Model Forcing Function for Variable Slope	p. 55
Derivation of Two-state Theory	p. 55
Derivation of the Extended Ternary Complex Model	p. 56
Dependence of Constitutive Activity on Receptor Density	p. 56
Derivation of the Cubic Ternary Complex Model	p. 56
References	p. 57
Pharmacological Assay Formats: Binding
The Structure of This Chapter	p. 59
Binding Theory and Experiment	p. 59
Saturation Binding	p. 60
Displacement Binding	p. 62
Kinetic Binding Studies	p. 67
Complex Binding Phenomena: Agonist Affinity from Binding Curves	p. 67
Experimental Prerequisites for Correct Application of Binding Techniques	p. 71
The Effect of Protein Concentration on Binding Curves	p. 71
The Importance of Equilibration Time for Equilibrium Between Two Ligands	p. 73
Chapter Summary and Conclusions	p. 73
Derivations	p. 74
Displacement Binding: Competitive Interactions	p. 74
Displacement Binding: Noncompetitive Interactions	p. 75
Displacement of a Radioligand by an Allosteric Antagonist	p. 75
Relationship Between IC[subscript 50] and K[subscript I] for Competitive Antagonists	p. 75
Maximal Inhibition of Binding by an Allosteric Antagonist	p. 76
Relationship Between IC[subscript 50] and K[subscript I] for Allosteric Antagonists	p. 76
Two-stage Binding Reactions	p. 76
The Effect of G-protein Coupling on Observed Agonist Affinity	p. 76
Effect of Excess Receptor in Binding Experiments: Saturation Binding Curve	p. 76
Effect of Excess Receptor in Binding Experiments: Displacement Experiments	p. 77
References	p. 77
Agonists: The Measurement of Affinity and Efficacy in Functional Assays
Functional Pharmacological Experiments	p. 79
The Choice of Functional Assays	p. 80
Recombinant Functional Systems	p. 84
Functional Experiments: Dissimulation in Time	p. 87
Experiments in Real Time Versus Stop Time	p. 88
The Measurement of Agonist Affinity in Functional Experiments	p. 89
Partial Agonists	p. 89
Full Agonists	p. 91
Estimates of Relative Efficacy of Agonists in Functional Experiments	p. 95
Chapter Summary and Conclusions	p. 96
Derivations	p. 96
Relationship Between the EC[subscript 50] and Affinity of Agonists	p. 96
Method of Barlow, Scott, and Stephenson for Affinity of Partial Agonists	p. 97
Measurement of Agonist Affinity: Method of Furchgott	p. 97
Maximal Response of a Partial Agonist Is Dependent on Efficacy	p. 98
References	p. 98
Orthosteric Drug Antagonism
Introduction	p. 99
Kinetics of Drug-Receptor Interaction	p. 99
Surmountable Competitive Antagonism	p. 102
Schild Analysis	p. 102
Patterns of Dose-Response Curves That Preclude Schild Analysis	p. 106
Best Practice for the Use of Schild Analysis	p. 107
Analyses for Inverse Agonists in Constitutively Active Receptor Systems	p. 108
Analyses for Partial Agonists	p. 111
The Method of Lew and Angus: Nonlinear Regressional Analysis	p. 113
Noncompetitive Antagonism	p. 114
Agonist-Antagonist Hemi-equilibria	p. 117
Resultant Analysis	p. 119
Chapter Summary and Conclusions	p. 120
Derivations	p. 121
Derivation of the Gaddum Equation for Competitive Antagonism	p. 122
Derivation of the Gaddum Equation for Noncompetitive Antagonism	p. 122
Derivation of the Schild Equation	p. 122
Functional Effects of an Inverse Agonist with the Operational Model	p. 123
pA[subscript 2] Measurement for Inverse Agonists	p. 123
Functional Effects of a Partial Agonist with the Operational Model	p. 124
pA[subscript 2] Measurements for Partial Agonists	p. 124
Method of Stephenson for Partial Agonist Affinity Measurement	p. 124
Derivation of the Method of Gaddum for Noncompetitive Antagonism	p. 125
Relationship of pA[subscript 2] and PK[subscript B] for Insurmountable Orthosteric Antagonism	p. 125
Resultant Analysis	p. 125
References	p. 126
Allosteric Drug Antagonism
Introduction	p. 127
The Nature of Receptor Allosterism	p. 127
Properties of Allosteric Modulators	p. 129
Functional Study of Allosteric Modulators	p. 134
Surmountable Allosteric Modulation ([Zeta] = 1)	p. 135
Insurmountable Allosteric Antagonism ([Zeta] = 0)	p. 136
Variable Effects on Efficacy ([Zeta Not Equal] 0)	p. 138
Measurement of the Potency of Allosteric Insurmountable Antagonists	p. 138
Methods for Detecting Allosterism	p. 140
Chapter Summary and Conclusions	p. 142
Derivations	p. 143
Allosteric Model of Receptor Activity	p. 143
Effects of Allosteric Ligands on Response: Changing Efficacy	p. 143
Schild Analysis for Allosteric Antagonists	p. 144
Relationship of pA[subscript 2] and pK[subscript B] for Insurmountable Allosteric Antagonism	p. 144
References	p. 145
The Process of Drug Discovery
Pharmacology in Drug Discovery	p. 147
Chemical Sources for Potential Drugs	p. 147
Pharmacodynamics and High-throughput Screening	p. 152
Pharmacokinetics	p. 162
Pharmaceutical Development	p. 169
Adverse Drug Effects	p. 169
Chapter Summary and Conclusions	p. 172
References	p. 172
Target- and System-based Strategies for Drug Discovery
Some Challenges for Modern Drug Discovery	p. 175
Target-based Drug Discovery	p. 175
Target Validation and the Use of Chemical Tools	p. 177
Recombinant Systems	p. 179
Defining Biological Targets	p. 180
Systems-based Drug Discovery	p. 184
In Vivo Systems, Biomarkers, and Clinical Feedback	p. 189
Types of Therapeutically Active Ligands	p. 190
Summary and Conclusions	p. 193
References	p. 196
"Hit" to Drug: Lead Optimization
Tracking SAR and Determining Mechanism of Action: Data-driven Drug-based Pharmacology	p. 199
Drug Initiation of Response: Agonism	p. 199
Analysis of Full Agonism	p. 200
Error and Agonist Dose-Response Curves	p. 202
Quantifying Full Agonist Potency Ratios	p. 202
Analysis of Partial Agonism	p. 204
Affinity-dependent versus Efficacy-dependent Agonist Potency	p. 204
Inhibition of Agonist Response: Antagonism	p. 206
"Short-form" Measures of Antagonism for Following Structure-activity Relationship	p. 209
Erroneous Application of Correction Factors to Noncompetitive Antagonists	p. 211
Noncompetitive Antagonism in Systems with Receptor Reserve	p. 214
Inhibition Curves for Allosteric Modulators	p. 214
Practical Application	p. 216
Summary and Conclusions	p. 218
Derivations	p. 218
System Independence of Full Agonist Potency Ratios: Classical and Operational Models	p. 219
Operational Model for Partial Agonist Interaction with Agonist: Variable Slope	p. 220
Operational Model for Inverse Agonist Interaction with Agonist: Variable Slope	p. 221
Surmountable Allosteric Antagonism: Variable Slope	p. 221
Functional Model for Hemi-equilibrium Effects: Variable Slope	p. 221
Allosteric Antagonism with Changes in Efficacy: Variable Slope	p. 221
Orthosteric Insurmountable Antagonism: Operational Model with Variable Slope	p. 222
Allosteric Insurmountable Antagonism: Operational Model with Variable Slope	p. 222
IC[subscript 50] Correction Factors: Competitive Antagonists	p. 223
References	p. 223
Statistics and Experimental Design
Structure of This Chapter	p. 225
Introduction	p. 225
Descriptive Statistics: Comparing Sample Data	p. 225
Gaussian Distribution	p. 225
Populations and Samples	p. 226
Confidence Intervals	p. 228
Paired Data Sets	p. 229
One-way Analysis of Variance	p. 229
Two-way Analysis of Variance	p. 231
Regression and Correlation	p. 231
Detection of Single Versus Multiple Populations	p. 232
How Consistent Is Experimental Data with Models?	p. 232
Comparison of Data to Models: Choice of Model	p. 232
Curve Fitting: Good Practice	p. 236
Outliers and Weighting Data Points	p. 237
Overextrapolation of Data	p. 239
Hypothesis Testing: Examples with Dose-response Curves	p. 239
One Curve or Two? Detection of Differences in Curves	p. 243
Asymmetrical Dose-Response Curves	p. 244
Comparison of Data to Linear Models	p. 246
Is a Given Regression Linear?	p. 246
One or More Regression Lines? Analysis of Covariance	p. 247
Comparison of Samples to "Standard Values"	p. 249
Comparison of Means by Two Methods or in Two Systems	p. 250
Comparing Assays/Methods with a Range of Ligands	p. 251
Experimental Design and Quality Control	p. 251
Detection of Difference in Samples	p. 251
Power Analysis	p. 252
Chapter Summary and Conclusions	p. 254
References	p. 254
Selected Pharmacological Methods
Binding Experiments	p. 255
Saturation Binding	p. 255
Displacement Binding	p. 255
Functional Experiments	p. 257
Determination of Equiactive Concentrations on Dose-response Curves	p. 257
Method of Barlow, Scott, and Stephenson for Measurement of the Affinity of a Partial Agonist	p. 260
Method of Furchgott for the Measurement of the Affinity of a Full Agonist	p. 261
Schild Analysis for the Measurement of Competitive Antagonist Affinity	p. 261
Resultant Analysis for Measurement of Affinity of Competitive Antagonists with Multiple Properties	p. 264
Method of Stephenson for Measurement of Partial Agonist Affinity	p. 266
Extension of the Stephenson Method: Method of Kaumann and Marano	p. 267
Method of Gaddum for Measurement of Noncompetitive Antagonist Affinity	p. 267
Measurement of the Affinity and Maximal Allosteric Constant for Allosteric Modulators Producing Surmountable Effects	p. 268
Measurement of pA[subscript 2] for Antagonists	p. 268
Method for Estimating Affinity of Insurmountable Antagonist (Dextral Displacement Observed)	p. 271
Method for Estimating Affinity of Insurmountable Antagonist (No Dextral Displacement Observed)	p. 273
Glossary of Pharmacological Terms	p. 277
Appendices
Statistical Tables	p. 283
Mathematical Fitting Functions	p. 287
Index	p. 293
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