Unit 4 Workbook Flashcards
DEPRESSION
- Hypothesis
- Pharmacological approaches
- Targets
- reduced central functioning of NA/serotonergic NT
- enhancement of synaptic NA/serotonin
- monoamine reuptake inhibitors, monoamine receptor antagonists, monoamine oxidase inhibitors
SCHIZOPHRENIA
- Hypothesis
- Pharmacological approaches
- Targets
- enhanced central functioning of dopaminergic NT
- reduction in dopamine receptor-mediated effects
- dopamine receptor antagonists, partial agonists
ANXIETY
- Hypothesis
- Pharmacological approaches
- Targets
- overactivity of central noradrenergic, underactivity of serotonergic and GABAergic systems
- restoration of normal activity of central transmitter systems
- benzodiazepine site of GABAA receptor complex, partial agonists of 5-HT1A receptors, serotonin reuptake inhibitors, noradrenergic receptor agonists
ALZHEIMER’S DISEASE
- Hypothesis
- Pharmacological approaches
- Targets
- neurodegeneration of central cholinergic neurons
- enhancement of synaptic ACh levels
- acetylcholinesterase inhibitors
PARKINSON’S DISEASE
- Hypothesis
- Pharmacological approaches
- Targets
- neurodegeneration of central dopaminergic neurons
- enhancement of synaptic dopamine levels
- increasing dopamine precursors, inhibition of MAO-B, dopamine receptor agonists
synaptosomes
a subcellular fraction obtained following the disruption and centrifugation of brain samples
The synaptosomes used in evaluating a drug’s binding are typically derived from rat brain
used to assess not only the affinity of the drug for the binding site of the target of interest (usually measured as a Ki, the dissociation equilibrium constant for an inhibitor) but also the relative affinity for a range of other proteins (including other receptors, neurotransmitter transport proteins, ion channels and enzymes) to determine selectivity
“classical” monoamine receptors
adrenergic (α1, α2, B1, B2);
dopamine (D1 -D5);
histamine (H1, H2);
muscarinic (M1-M5);
serotonin: (5-HT1A, 5-HT1B, 5-HT2A, 5-HT2C, 5-HT3, 5-HT5A, 5-HT6, 5-HT7)
AA based receptors
GABA
benzodiazepine (BZD central, BZD peripheral)
phencyclidine (PCP) sits on NMDA receptor
neuropeptide receptors
angiotensin-II: AT1, AT2; bombesin; bradykinin (B2); calcitonin gene-related peptide (CGRP); cholecystokinin (CCKA, CCKB); endothelin (ETA, ETB); galanin: GAL1, GAL2); Growth factors, cytokines, chemokines: CXCR2, TNF-α, CCR1; melanocortin (MC4); neurokinin (NK1, NK2, NK3); neuropeptide Y (Y1, Y2); neurotensin (NT1, NT2); opiate: gamma, kappa, μ, orphanin: ORL1); PACAP (PAC1); somatostatin (Sst); vasopressin: (V1a); vasoactive intestinal peptide (VIP1)
other receptors
adenosine (A1, A2, A3); cannabinoid (CB1, CB2); prostanoid (P2X, P2Y); sigma σ
transporters
dopamine DA
noradrenaline NA
serotonin 5-HT
enzymes
Cyclooxygenase (COX-1, COX-2); acetylcholinesterase (AChE)
when is an affinity for more than 1 target desirable
dual reuptake inhibitor antidepressants (increase no. of patients that will respond)
D2/5-HT2 receptor antagonism that is a property of many of the more recently introduced antipsychotic agents (reduce adverse effects)
occupancy of a given concentration of a drug for its receptor equation
competitive antagonist
it should be able to displace the radioligand and generate a reverse sigmoid curve
IC50 value
The antagonist concentration that produces a 50% reduction in binding
similar to EC50
Cheng-Prusoff equation
3 mechanisms by which CNS drugs exert their effect
affinity for target
inhibition of reuptake
inhibition of enzyme activity
vilazodone
anti-depressant
In addition to 5-HT reuptake inhibition, vilazodone displays partial agonist properties at the 5-HT1A receptor, and these combined effects are believed to have antidepressant properties, whilst reducing the extent of serotonin-mediated adverse effects seen with SSRI antidepressants
3 AChesterase inhibitors
high affinity for H1 receptors
sedating and weight gain properties
α1 blockade
associated with a potential to produce postural (orthostatic) hypotension
fluoxetine
SSRI
selectivity for a single target, i.e. the 5-HT reuptake site and as a result has a “cleaner” safety profile than amitriptyline with most of its adverse effects associated with the serotonergic system
venlafaxine
roughly equivalent inhibition of noradrenaline and 5-HT reuptake and is known as a dual uptake inhibitor
mirtazapine
“atypical” profile in that has no affinity for reuptake sites, and instead exerts its antidepressant effects by blocking the α2 and 5-HT2A receptors
its sedating effects can be attributed to high affinity for the H1 receptor
in vitro profile for antidepressant drugs
darker colour => greater affinity for the target => low Ki value
face validity
how well the model simulates symptoms of the disease - core features of the disase to be modelled as identified in the diagnostic criteria
this is easier in some behaviours e.g. anhedonia, memory loss, than others (cognitive dysfunction)