pharm ch 18
receptor sites for the catecholamines norepinephrine and epinephrine
where are alpha1 receptor located?
postsynaptic effector cells
where are alpha2 receptor located?
presynaptic nerve terminals
they control release of neurotransmitter
alpha 1 and 2
what is the predominant alpha-adrenergic agonist response?
vasoconstriction and CNS stimulation
where are beta-adrenergic receptor located?
they are all located on postsynaptic effector cells
what are beta-adrenergic agonist response result?
results in bronchial, GI, uterine smooth muscle relaxation; glycogenolysis and cardiac stimulation
2 enzyme that metabolize catecholamines
monoamine oxidase (MAO) and catechol orthomethyltransferase (COMT)
enzyme that breaks down catecholamines that are i nerve ending
enzyme that breaks down catecholamines that are outside the nerve ending at the synaptic cleft
adrenergic synthetic substances
noncathecholamine adrenergic drugs. they have longer duration of action
used to support the cardiovascular system during cardiac failure or shock
vasoactive symphathomimetics, vasoconstrictive drugs (vasopressive), inotropes or cardioselective sympathomimetics
unwanted CNS effects of the alpha-adrenergoc drugs
possible cardiovascular adverse effect if the alpha-adrenergic drugs
palpitations and dysrhythmias
beta-adrenergic drugs can adversely stimulate the CNS causing:
increase heart rate
pharm ch 18