L1- Introduction Flashcards
endogenous
from within the body e.g. hormones
exogenous I
natural but from the outside e.g. plant based- antibiotics, morphine etc
exogenous II
synthetic- man made
main extracellular signalling groups
endocrine paracrine autocrine
endocrine paracrine autocrine defined by
distance and volume
endocrine hormones circulate
the whole body
endocrine glands are highly
potent
where will endocrine hormones act on
tissues with correct receptors
endocrine signals are subject to
tight feedback control
types of endocrine signalling molecules
Hydrophilic 1
Hydrophilic 2
Lipophilic
Hydrophilic 1
catecholamines
amines
Amino acid derivatives – small charged hydrophilic with receptors in plasma membrane
Hydrophilic 2
Peptides and proteins
Peptides and proteins receptors in
the plasma membrane
Lipophilic
steroids
steroids
common derivation from cholesterol.
- receptors are intracellular
catecholamines are
hydrophilic and act on the plasma membrane
peptides and proteins are
hydrophilic and work on the plasma membrane (more slowly than catecholamines)
steroids
lipophilic and work on cytosolic and nuclear receptors
paracrine signalling
short distance signalling e.g. from cell to cell or nearby cells
paracrine molecules are released into
the extracellular environment
paracrine molecules induce
changes in receptor cells
example of paracrine signalling
NT at synaptic junctions
neurotranmitters
electrochemical signals that travel 20nm to cross synaptic junctions in less than a msec
major groups of NT
amino acids, monoamines, peptides, Ach
Ach- excitatory or inhibitory
Excitatory
Adrenaline- excitatory or inhibitory
Excitatory
Noradrenaline- excitatory or inhibitory
Excitatory
Dopamine- excitatory or inhibitory
Excitatory and inhibitory
Seratonin- excitatory or inhibitory
Excitatory
adrenaline, noradrenaline, dopamine and seratonin are what types of NT
monoamines
name some amino acid NTs
glutamate glycine and GABA
Glutamate- excitatory or inhibitory
Excitatory
Glycine- excitatory or inhibitory
mainly inhibitory
Gaba- excitatory or inhibitory
Inhibitory
endogenous molecules
made by self
- engineered by evolution to carry and transfer specific signal
- optimal for job
exogenous molecules
drugs
- engineered by human design to carry and transfer ‘imposter’ signal
- fit may be sub-optimal or antagonistic
what is possible with exogenous molecules
side effects
Signal molecules target (acronym)
RITE
R stands for
receptor
I stands for
Ion channel
examples of ion channels
- ligand gates
- voltage agted
- GPCR
T stands for
transporters
E stands for
Enzymes
exceptions to RITE
- Chemotherapy: target is structural protein or DNA
- Antibiotics- kill specific organism
- Drug which kills specific cancer cells
receptors acronyms
KING
K
kinase linked receptors
I
ion channel
N
nuclear/ intracellular
G
GPCR
example ligand-gated ion channel (inotropic)
Nictoninc
Ach receptor
example GPCR
Muscarinic
ACh receptor
example Kinase-linked receptors
cytokine receptors (TFs)
example Nuclear receptors
steroids- oestrogen receptor