Cardiovascular Pharmacology 1 Review

Flashcards covering key concepts from cardiovascular pharmacology, focusing on calcium regulation, muscle contraction mechanisms, and the influence of drugs.

Contractile Mechanisms

The processes by which muscle fibers generate force and shorten, essential to skeletal, cardiac, and smooth muscle function.

Sarcoplasmic Reticulum (SR)

An intracellular membrane-bound structure that stores calcium ions and releases them during muscle contraction.

Voltage Gated Calcium Channels (VGCC)

Channels that open in response to membrane depolarization and allow Ca2+ influx into the cell.

L Type Ca2+ Channels

Voltage gated channels in the skeletal, cardiac and smooth muscle.

N Type and P/Q Type Ca2+ Channels

Voltage-gated calcium channels primarily located in presynaptic neurons and cardiac muscle, responsible for neurotransmitter release and excitation-contraction coupling.

R Type Ca2+ Channels

Voltage-gated calcium channels found in the CNS.

T Type Ca2+ Channels

Voltage gated Ca2+ channels found in rapid firing cells such as the SA node and in thalamus neurons.

Cytoplasmic Ca2+ 

Stored in the endoplasmic/sarcoplasmic reticulum and mitochrondria. The concentration is highly regulated to maintain a concentration of approximately 100 nM.

Ligand Gated Calcium Channels

Channels that open in response to the binding of a specific ligand, neurotransmitters, allowing calcium ions to enter the cell.

NMDA Type Glutamate Receptor

Ligand gated Ca2+ channel that can cause so much Ca2+ entry that the cell dies.

P2X Receptor

The only true ligand gated Ca2+ channel in smooth muscle activated by ATP. It is highly permeable to Ca2+ but also allows the entry of other ions.

Calcium-Release-Activated Calcium (CRAC) Channels

Store operated Ca2+ channels activated by the depletion of calcium in the sarcoplasmic reticulum, allowing entry of extracellular calcium.

Na+-Ca2+ Exchanger (NCX)

A transport mechanism that exchanges 3 sodium ions into the cell for 1 calcium ion out of the cell.

Na+/K+ ATPase

An electrogenic pump that moves 3 sodium out of and potassium into the cell, influencing the resting membrane potential.

Inositol tris-phosphate (IP3) receptor

A receptor that, when activated, triggers the release of calcium from the sarcoplasmic reticulum.

Calmodulin

A calcium-binding protein that mediates various cellular responses to changes in intracellular calcium concentration.

Skeletal Muscle Contraction

A process involving depolarization, calcium release from the sarcoplasmic reticulum, and actin-myosin binding.

Cardiac Muscle Contraction

A process reliant on calcium entry through L-type calcium channels and triggered by depolarization.

Smooth Muscle Contraction

A process that does not involve troponin, but instead utilizes myosin light chain kinase (MLCK) to facilitate contraction.

Digoxin

A cardiac glycoside that inhibits Na+/K+ ATPase, affecting cardiac muscle contractility.

Caffeine

A methylxanthine that sensitizes the ryanodine receptor and promotes calcium release from the endoplasmic reticulum.

Pharmacological Relevance

The study of drug effects on muscle contraction and how various drugs can modify physiological responses.

Contractile Mechanisms

The processes by which muscle fibers generate force and shorten, essential to skeletal, cardiac, and smooth muscle function.

Sarcoplasmic Reticulum (SR)

An intracellular membrane-bound structure that stores calcium ions and releases them during muscle contraction.

Voltage Gated Calcium Channels (VGCC)

Channels that open in response to membrane depolarization and allow Ca2+ influx into the cell.

Ligand Gated Calcium Channels

Channels that open in response to the binding of a specific ligand, allowing calcium ions to enter the cell.

Calcium-Release-Activated Calcium (CRAC) Channels

Channels activated by the depletion of calcium in the sarcoplasmic reticulum, allowing entry of extracellular calcium.

Na+-Ca2+ Exchanger (NCX)

A transport mechanism that exchanges 3 sodium ions into the cell for 1 calcium ion out of the cell.

Na+/K+ ATPase

An electrogenic pump that moves 3 sodium out of and potassium into the cell, influencing the resting membrane potential.

Inositol tris-phosphate (IP3) receptor

A receptor that, when activated, triggers the release of calcium from the sarcoplasmic reticulum.

Calmodulin

A calcium-binding protein that mediates various cellular responses to changes in intracellular calcium concentration.

Skeletal Muscle Contraction

A process involving depolarization, calcium release from the sarcoplasmic reticulum, and actin-myosin binding.

Cardiac Muscle Contraction

A process reliant on calcium entry through L-type calcium channels and triggered by depolarization.

Smooth Muscle Contraction

A process that does not involve troponin, but instead utilizes myosin light chain kinase (MLCK) to facilitate contraction.

Digoxin

A cardiac glycoside that inhibits Na+/K+ ATPase, affecting cardiac muscle contractility.

Caffeine

A methylxanthine that sensitizes the ryanodine receptor and promotes calcium release from the endoplasmic reticulum.

Pharmacological Relevance

The study of drug effects on muscle contraction and how various drugs can modify physiological responses.

Ryanodine Receptor (RyR)

A calcium release channel located on the sarcoplasmic reticulum membrane, primarily responsible for releasing stored calcium into the cytoplasm during muscle excitation-contraction coupling in skeletal and cardiac muscle.

Dihydropyridine Receptor (DHPR)

A voltage-gated calcium channel (L-type) that acts primarily as a voltage sensor in skeletal muscle, physically interacting with the ryanodine receptor, and as a primary calcium entry channel in cardiac and smooth muscle.

SERCA Pump

Sarco/endoplasmic reticulum calcium ATPase, a pump that actively transports Ca2+ from the cytoplasm back into the sarcoplasmic reticulum, leading to muscle relaxation.

Calcium-Induced Calcium Release (CICR)

A mechanism unique to cardiac muscle where a small influx of extracellular Ca2+ through DHPR (L-type Ca2+ channels) triggers a much larger release of Ca2+ from the sarcoplasmic reticulum via RyR channels.

Myosin Light Chain Kinase (MLCK)

An enzyme in smooth muscle that, when activated by Ca2+-calmodulin, phosphorylates myosin light chains, leading to increased myosin ATPase activity and muscle contraction.