Alpha and Beta Blockers Pharmacology

Neurotransmitter released from adrenergic neurons, made from tyrosine, a specific amino acid. It binds to various receptors, influencing different physiological effects.

A co-transporter in nerve terminals responsible for taking up tyrosine, the precursor molecule for norepinephrine.

Substance produced from tyrosine in nerve terminals, converted into norepinephrine within vesicles. It acts as a neurotransmitter and plays a role in regulating various bodily functions.

Small membrane-bound sacs containing norepinephrine within nerve terminals. They store and release norepinephrine upon stimulation.

A protein channel in the neuron's membrane that opens in response to an action potential. It allows calcium ions to flow into the cell, triggering the release of neurotransmitters, such as norepinephrine.

Process by which vesicles containing neurotransmitters fuse with the cell membrane and release their contents into the synaptic space.

A type of receptor that binds to norepinephrine, located on various cells and tissues. It is involved in regulating various physiological processes, including blood pressure, heart rate, and smooth muscle contraction.

A subtype of alpha receptor that couples to the Gq protein and increases intracellular calcium levels. It is found on smooth muscle cells of blood vessels and other tissues, leading to vasoconstriction and increased blood pressure.

A subtype of alpha receptor that couples to the Gi protein and decreases intracellular cyclic AMP levels. It is found on presynaptic neurons, inhibiting norepinephrine release and decreasing sympathetic tone.

A type of receptor that binds to norepinephrine, located on various cells and tissues. It is involved in regulating various physiological processes, including heart rate, contractility, and smooth muscle relaxation.

A subtype of beta receptor that couples to the Gs protein and increases intracellular cyclic AMP levels. It is found on the heart, causing increased heart rate, contractility, and secretion.

A subtype of beta receptor that couples to the Gs protein and increases intracellular cyclic AMP levels. It is found on various tissues, causing vasodilation, bronchodilation, and glycogenolysis in the liver.

A catecholamine like norepinephrine released from the adrenal medulla. It preferentially binds to beta receptors, particularly beta-2 receptors, causing various physiological effects.

An enzyme that converts norepinephrine into an inactive metabolite. This process helps terminate the action of norepinephrine.

Drugs that block the effects of norepinephrine by binding to alpha receptors. They are used to treat conditions like hypertension and urinary retention caused by benign prostatic hyperplasia (BPH).

Drugs that block the effects of norepinephrine and epinephrine by binding to beta receptors. They are used to treat conditions like high blood pressure, arrhythmias, and angina.

A potential adverse effect of alpha blockers, characterized by a sudden drop in blood pressure upon standing. It occurs because alpha blockers reduce venous return to the heart, decreasing blood pressure.

A condition where the iris, a colored part of the eye, becomes floppy during surgery. It is caused by alpha blockers, which constrict the pupil, affecting the iris muscles.

A specific effect of using alpha blockers, particularly alpha-1 blockers, to treat urinary retention caused by benign prostatic hyperplasia (BPH). It works by relaxing the muscles in the bladder neck, making urination easier.

Drugs that block the effects of alpha-1 receptors, causing relaxation of smooth muscle in blood vessels, sphincters, and the pupil. They are used to treat conditions like hypertension, BPH, and Raynaud's phenomenon.

Drugs that block the effects of beta-1 receptors, causing a decrease in heart rate and contractility. They are used to treat conditions like high blood pressure, angina, and arrhythmias.

A potential adverse effect of beta-1 blockers, characterized by a slow heart rate. It can be more pronounced in individuals with pre-existing heart problems or taking other medications that slow the heart rate.