Phosphodiesterase III Flashcards
Which enzyme metabolizes cyclic adenosine monophosphate (cAMP)?
Study on!!!
What molecule is considered the energy of life?
ATP
(adenosine triphosphate)
Through its high energy —– bonds, ATP stores energy that we obtain from food
phosphate bonds,
Through its high energy phosphate bonds, ATP stores energy that we obtain from food and acts as the molecular unit of currency of —– transfer.
energy transfer
In the presence of oxygen, —– moles of ATP can be produced from 1 mole of glucose.
38 moles of ATP
Beta —– receptors are present in the heart
Beta-1 receptors
Beta-1 receptors are present in the heart, while —– receptors are present in skeletal muscle and other vascular beds, such as the myocardium
beta-2 receptors
Beta receptor stimulation activates a —– G-protein
Stimulatory G-protein
(Gs)
Beta receptor stimulation activates a stimulatory G-protein (Gs) and instructs —– to convert ATP into —–.
Adenylate cyclase
cAMP
(cyclic adenosine monophosphate)
cAMP is responsible for “turning on” a variety of —– that instruct the cell to perform a specific function.
protein kinases
—– metabolizes cAMP to AMP (adenosine monophosphate).
Phosphodiesterase Ill
Phosphodiesterase Ill metabolizes cAMP to AMP (adenosine monophosphate). This “—–” these protein kinases, and the cell is no longer instructed to perform that specific function
“turns off”
By inhibiting the “turn off” mechanism, inhibition of phosphodiesterase Ill indirectly increases —–.
intracellular cAMP
By inhibiting the “turn off” mechanism, inhibition of phosphodiesterase Ill indirectly increases intracellular cAMP and maintains the protein kinases in the “—–” state
“turned on”
In the cardiac muscle cell, cAMP augments myocardial performance by increasing intracellular —– and the force of —–.
intracellular calcium and the
force of contraction
In the cardiac muscle cell, cAMP increases the rate of myocardial relaxation by accelerating the return of —– to the sarcoplasmic reticulum
Calcium
The process of increasing the rate of myocardial relaxation by accelerating the return of calcium to the sarcoplasmic reticulum is called —–.
Lusitropy
In the vascular smooth muscle cell, cAMP inhibits —– kinase
myosin light chain kinase
In the vascular smooth muscle cell, cAMP inhibits myosin light chain kinase. This causes
Vasodilation
Decreased SVR
Which drug is an example of a PDE Ill inhibitors?
Milrinone
PDE Ill inhibitors, such as milrinone, are also called —–.
Inodilators
PDE Ill inhibitors, such as milrinone, are also called inodilators. They augment myocardial performance independently of the
—– nervous system
Sympathetic nervous system
PDE Ill inhibitors, such as milrinone, are also called inodilators. They augment myocardial performance independently of the sympathetic nervous system. This feature makes PDE Ill inhibitors useful in which drug-induced myocardial depression
Beta-blocker induced myocardial depression
PDE Ill inhibitors, such as milrinone, are also called inodilators. They augment myocardial performance independently of the sympathetic nervous system. This feature makes PDE Ill inhibitors useful in —– heart failure
Acute heart failure
PDE Ill inhibitors, such as milrinone, are also called inodilators. They augment myocardial performance independently of the sympathetic nervous system. This feature makes PDE Ill inhibitors useful in unresponsiveness to IV —–.
Catecholamines
PDE Ill inhibitors, such as milrinone, are also called inodilators. They augment myocardial performance independently of the sympathetic nervous system. This feature makes PDE Ill inhibitors useful anytime the combination of increased —– and reduced —– would be desirable
increased inotropy and
reduced afterload
In case you were wondering, there are —– different varieties of phosphodiesterase
Five
Phosphodiesterase (I-V).
PDE Ill is specific to which intracellular second messenger?
cAMP
While PDE Ill is specific for cAMP, the other forms of PDE are
—– specific to cAMP
Not specific to cAMP
—– is the prototype nonselective phosphodiesterase inhibitor
Theophylline
Which enzyme metabolizes cyclic adenosine monophosphate?
Phosphodiesterase III
—– is an effector that converts ATP to cAMP (the second messenger).
Adenylate Cyclase
cAMP activates —–, which initiates a variety of phosphorylation reactions inside the cell
protein kinase A
Phosphodiesterase Ill essentially “—–” cAMP by metabolizing it to AMP
“turns off”
References:
- Barash. Clinical Anesthesia. 8th ed**.* 2017. p. 321-322.
- Hemmings* . Pharmacology and Physiology for Anesthesia: Foundations and Clinical Application . 1st ed.* *2013. p.* *391. Flood. Stoel**ting’s Pharmacology & Physiology in Anesthetic Practice. 5th ed. 2015. p. 468-469, 684.
