vasoconstrictor Flashcards
hockerman
what are the GPCRs that are coupled to vasconstriction?
alpha-1 adrenergic
angiotensin 1
endothelin A
vasopressin 1
5HT2A
what is the molecular basis for vasconconstriction?
alpha 1 adrenergic receptors
what is mechanism for vasconstriction?
Calcium influx into the smooth muscle cell leads to an increase in calcium –> Ca²⁺ binds to calmodulin, activating MLCK –> MLCK phosphorylates the myosin light chains –> Phosphorylated myosin binds to actin –> the actin-myosin interaction causes smooth muscle contraction and vasoconstriction
what is modulation of vascular smooth muscle?
resistance vessels
controlling blood flow
cerebral arteries
what makes up controlling blood flow?
surgical procedures
nasal congestion
blood shot eyes
what makes up cerebral arteries in relation to modulation of vascular smooth muscle?
migraine/ischemic damage
what are the therapeutic uses of vasconstrictors?
hypotension
blood flow control (reduction)
what are the causes of hypotension?
shock (anaphylactic, brain trauma, hemorrhagic)
anesthesia (spinal)
chronic orthostatic hypotension
what drug class is used for hypotension?
alpha-1 adrenergic receptor agonists
what drugs are alpha1 adrenergic receptor agonists?
epinephrine
phenylephrine
midodrine
droxidopa
what is epinephrine?
used adjunct to local anesthetics to reduce blood flow to site of injection
how is epinephrine used?
decreased toxicity
lower dose required
longer duration
what drugs are used for hemostasis during surgery?
epinephrine and cocaine
what is hemostasis?
stoppage of bleeding
what is the purpose of nasal and ophthalmic decongestants?
vasoconstriction in the nasal mucosa or conjunctiva
