Pharmacodynamics Flashcards

This set of vocabulary flashcards covers the fundamental principles of pharmacodynamics, including receptor types, signaling mechanisms, and drug interaction properties as presented by Dr. Claire Kelly.

Pharmacodynamics

The study of how a drug effects biochemical, molecular, and physiological processes at the cellular and organ level; often described as "what the drug does to the body."

Agonist

A ligand that binds to a receptor and produces a biological response.

Antagonist

A ligand that binds to a receptor but produces no response, effectively blocking the primary ligand.

Ligand-gated ion channels

Receptors where the binding of a ligand (such as a neurotransmitter) opens a channel to allow rapid effects; examples include $Ach$ (excitatory) and $GABA$ (inhibitory).

G-protein coupled receptors (GPCRs)

The largest and most diverse family of receptors consisting of three subunits ($\alpha\beta\gamma$).

$\alpha$ subunit

The part of a G-protein that functions as a GTPase and is linked to effector enzymes, channels, or carrier proteins.

Adenylate Cyclase ($AC$)

A GPCR effector enzyme that produces $cAMP$, which then activates protein kinase A ($PKA$).

$$G\alpha_s$$

A stimulatory G-protein subunit.

$$G\alpha_i$$

An inhibitory G-protein subunit.

Phospholipase C ($PLC$)

A GPCR effector linked to signaling through $IP_3$, $DAG$, and the $\alpha_1$-adrenoreceptor.

Enzyme-linked receptors

Receptors important for hormones, growth factors, and cytokines (e.g., Insulin) that typically dimerise and are coupled to kinases like receptor tyrosine kinases.

Nuclear Receptors

Ligand-activated transcription factors that interact with DNA directly to modify transcription; their ligands are normally lipid-soluble, such as endocrine steroid hormones.

Selectivity

A factor affecting receptors that refers to their ability to bind to either a single or multiple ligands.

Affinity

The strength of a drug-receptor interaction.

Intrinsic activity (efficacy)

The ability of a drug-receptor interaction to produce a physiological response.

Upregulation

The regulation process where receptor sensitivity or number increases, as seen with Propranolol.

Downregulation

The regulation process where receptor sensitivity or number decreases, as seen with Salbutamol.

JAK-STAT-kinase

A specific type of kinase pathway associated with enzyme-linked receptors.