09.29.17 Receptor Coupling Mechanisms Flashcards
Compare pharmacokinetics to pharmacodynamics
- Pharmacokinetics: body’s effect on drugs
- Pharmacodynamics: drug’s effect on body
Give two examples of when a receptor can also be an effector:
- kinase-linked receptor (eg. Tyrosine kinase: insulin)
- ion-channel (eg. Nicotinic ACh receptor)
What is the minimum number of contact points required between a drug and its receptor to see a difference in activity?
3
Give five regulatory advantages in having a second messenger system:
- influence cell from outside
- localization
- primary signal can be amplified
- multiple inputs to common 2nd messenger
- complexity generates many different control points
List common 2nd messengers (6):
- cAMP
- cGMP
- Ca
- phosphoinositide breakdown products (IP3, DAG)
- arachidonic acid derivatives from lipids
- NO
Give some examples of first messengers (2):
Adrenaline, epinephrine
Describe a few physiological processes controlled by cAMP:
- metabolic (glycogenolysis, gluconeogenesis, lipolysis)
- release of hormones, neurotransmitters
- smooth muscle contractility (relaxation, except in heart muscle)
- membrane permeability
- steroidogenesis
- ion channel function
- cell proliferation
- cell differentiation
- gene transcription
- memory formation
- melatonin synthesis in pineal
Describe the enzymes/products in synthesis/degradation of cAMP, cGMP:
ATP (AC) —> cAMP (PDE) —> 5’-AMP
GTP (GC) —> cGMP (PDE) —>5’-GMP
Xanthine, caffeine, theobromine, theophylline
Class: Methylxanthines
MOA: inhibition of PDE, simulate AC resulting in increased cAMP
Sildenafil
MOA: PDE5 inhibition, result in increased blood flow to penis, vascular smooth muscle relaxation
