Lecture 81 Flashcards
_____ is considered a third generation beta blocker, but is technically a PARTIAL ______ to Beta receptors (remember how partials can act with respect to full…) and Alpha1 _____.
LABETALOL
Partial Agonist
Alpha1 antagonist (blocker)
_____ is an INDIRECT antagonist (depletor) and acts by blocking the intracellular uptake of any catecholamine into the storage vesicles in the SNS –> ____ levels of NE at effector junction because it’s broken down in the cell by ____ if it’s not in the vesicle, and stops being made because ____ can’t get into the vesicle to be converted to NE (intracellular negative feedback of DA production).
RESERPINE is an INDIRECT antagonist and acts by blocking the uptake of any catecholamine into the storage vesicles in the SNS –> DECREASE levels of NE because it’s broken down in the cell by MAO if it’s not in the vesicle, and stops being made because DA can’t get into the vesicle to be converted to NE.
Reserpine is used to treat hypertension because over the course of about 2 weeks of treatment, it will ______ overall sympathetic tone due to its depleting effect on NE. It can potentially mimic symptoms of ______, because it has this depleting effect on DA in the Substantia Nigra (its effects are observed in the CNS as well as the PNS.)
It will DECREASE overall Sympathetic tone because of its depleting effect on NE. It can potentially mimic symptoms of PARKINSON’S, because it has this depleting effect on DA in the Substantia Nigra as well.
CAT (Choline Acetyltransferase) is the enzyme that catalyzes the formation of ACh from Choline and AcetylCoA. This occurs _____ the storage vesicle, which is opposite from NE production.
This occurs OUTSIDE the vesicle
Unlike with the SNS, the Parasymp doesn’t have Uptake transporters. Instead ACh is broken down by the enzyme _____, which has extremely high activity, converting ACh to ____ and ____. Keep in mind there are two enzymes referred to by the term “cholinesterase.” They are _____ and _____.
CHOLINESTERASE, which has extremely high activity, converting ACh to CHOLINE and ACETATE.
They are ACETYLCHOLINESTERASE and PSEUDOCHOLINESTERASE.
Botulinum toxin prevents the release of ACh by preventing _____ fusion with the membrane. This can be therapeutic for patients suffering from _____ palsy (prevents muscle spasticity), by injecting the toxin into muscles.
Prevents VESICLE fusion with the membrane. This can be therapeutic for patients suffering from CEREBRAL palsy.
_____ _____ venom causes the opposite effect of Botulinum toxin –> cause ALL of the ACh vesicles to fuse and release their contents
Black Widow
Muscarinic receptors are this kind ______ (acronym)
GPCRs
Although there isn’t Parasymp innervation of Vascular endothelial cells, they still contain Muscarinic receptors, activation of which will cause vaso______. Keep in mind that because there is no innervation, there’s no such thing as ______ action (they’re not normally active in the first place.)
Activation of vascular endothelial cell muscarinic receptors causes vasoDILATION. Keep in mind there’s no such thing as ANTAGONISTIC action of vascular endothelial muscarinic receptors.
When the ciliary muscle of the eye is inactive because of cholinergic blockade, the affected individual will experience ______, whereby they have issues with close up vision (20ft or closer.) This is an issue for patients with ______, for whom muscarinic antagonists are contraindicated.
The affected individual will experience CYCLOPLEGIA. This is an issue for patients with GLAUCOMA, for whom muscarinic atangonists are contraindicated.
Carbachol is a _____ acting cholinergic ______. It is not hydrolyzed by cholinesterases, and is used topically to treat _______. There is very minimal systemic effect because the dosage used is very small.
Carbachol is a DIRECT acting cholinergic AGONIST. It is not hydrolyzed by cholinesterases, and it is used topically to treat GLAUCOMA.
Bethanechol is a _____ acting cholinergic _____, but unlike Acetylcholine and Carbachol, it does NOT have _____ activity. It is used to treat Paralytic Ileus (lack of peristalsis due to young or old age, infectionmin the peritoneal cavity, or surgical complication), and Bladder Atony (lack of urination even though the bladder is filling - caused by same things as Paralytic Ileus.)
Bethanechol is a DIRECT acting Cholinergic AGONIST, but unlike Acetylcholine and Carbachol, it does NOT have NICOTINIC activity.
Pilocarpine is a _____-acting cholinergic ______ and has only ______ activity (which is good because it won’t act at Neuromuscular junctions or Ganglia.) It can be applied topically to the eye to treat ______, or can be taken orally to treat ______ (decreased saliva production.)
Pilocarpine is a DIRECT-acting cholinergic AGONIST and has only MUSCARINIC activity. I can be applied topically to the eye to treat GLAUCOMA, or taken orally to treat XEROSTOMIA.
Serious adverse effects usually only seen in cases of overdose of direct acting cholinergic agonists include ______ (acronym - what does it stand for? Aka Cholinergic crisis) and a burning sensation in the chest caused by _____ smooth muscle contraction.
Serious adverse effects include SLUD (excess Salivation, Lacrimation, Urination, and Defecation) and a burning sensation in the chest caused by BRONCHIOLAR smooth muscle contraction.
The following describes the function of Acetylcholinesterase: ACh acetylates the ____ OH group in the active site of acetylcholinesterase (inactivates the enzyme,) leaving the Choline behind. The acetylated enzyme is RAPIDLY (on the order of 20,000 rxn/sec) hydrolyzed (enzyme is reactivated.) The hydrolyzed product is ______.
ACh acetylates the SERINE OH group of the acetylcholinesterase.
The hydrolyzed product is ACETATE.
