ATC code C02

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

A sympatholytic is a medication which inhibits the functioning of the sympathetic nervous system (SNS). They are used as antihypertensives.

They mainly comprise antiadrenergic agents, but also anticholinergics in the case of the nicotinic antagonist, since nicotinic receptors relay the signals of the SNS across the ganglia.

Antiadrenergic agents inhibit the signals of adrenaline and noradrenaline. They are mainly adrenergic antagonists, inhibiting adrenergic receptors, but there are exceptions: clonidine is an adrenergic agonist on the α2 receptor, since this receptor is located presynaptically to inhibit further release of adrenaline and noradrenaline.

Other ways of inhibiting adrenergic signaling is by catecholamine synthesis blocking, e.g. by methyltyrosine. Reserpine works by inhibiting transport into synaptic vesicles of noradrenaline by inhibiting the VMAT transporter.

Many antiadrenergic agents used as antihypertensives include:

• centrally acting:
  • Clonidine (α2 agonist)
  • Guanfacine (α2 agonist)
  • Methyldopa (α2 agonist)
  • Moxonidine (imidazoline receptor agonist)
  • Rescinnamine (ACE inhibitor)
  • Reserpine (VMAT inhibitor)
  • Rilmenidine (imidazoline receptor agonist)
• ganglion-blocking
  • Mecamylamine (α3β4 nicotinic receptor inhibitor)
  • Trimethaphan (ganglion type receptor inhibitor)
• peripherally acting
  • Prazosin (α1 antagonist)
  • Guanethidine (Magnesium-ATPase inhibitor)
  • Indoramin (α1 antagonist)
  • Doxazosin (alpha blocker)

• Sympatholytics at the US National Library of Medicine Medical Subject Headings (MeSH)
• Template:Dorlands

Template:WikiDoc Sources

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

In anatomy, a ganglion (pl. ganglia) is a tissue mass, composed mainly of somata and dendritic structures, that often interconnects with other ganglia to form a complex system of ganglia known as a plexus. Ganglia provide relay points and intermediary connections between different neurological structures in the body, such as the peripheral and central nervous systems.

There are two major groups of ganglia: dorsal root ganglia (also known as the spinal ganglia) and autonomic ganglia. The former contains the cell bodies of sensory (afferent) nerves and the latter contains the cell bodies of autonomic nerves.

In the autonomic nervous system, fibers from the central nervous system to the ganglion are known as preganglionic fibers, while those from the ganglion to the effector organ are called postganglionic fibers.

In the brain, basal ganglia is a group of nuclei interconnected with the cerebral cortex, thalamus and brainstem, associated with a variety of functions: motor control, cognition, emotions and learning.

• Dorsal root ganglion
• Ganglion cell
• Ganglion cyst
• Nervous system
• Neuron

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

A sympatholytic is a medication which inhibits the functioning of the sympathetic nervous system (SNS). They are used as antihypertensives.

They mainly comprise antiadrenergic agents, but also anticholinergics in the case of the nicotinic antagonist, since nicotinic receptors relay the signals of the SNS across the ganglia.

Antiadrenergic agents inhibit the signals of adrenaline and noradrenaline. They are mainly adrenergic antagonists, inhibiting adrenergic receptors, but there are exceptions: clonidine is an adrenergic agonist on the α2 receptor, since this receptor is located presynaptically to inhibit further release of adrenaline and noradrenaline.

Other ways of inhibiting adrenergic signaling is by catecholamine synthesis blocking, e.g. by methyltyrosine. Reserpine works by inhibiting transport into synaptic vesicles of noradrenaline by inhibiting the VMAT transporter.

Many antiadrenergic agents used as antihypertensives include:

• centrally acting:
  • Clonidine (α2 agonist)
  • Guanfacine (α2 agonist)
  • Methyldopa (α2 agonist)
  • Moxonidine (imidazoline receptor agonist)
  • Rescinnamine (ACE inhibitor)
  • Reserpine (VMAT inhibitor)
  • Rilmenidine (imidazoline receptor agonist)
• ganglion-blocking
  • Mecamylamine (α3β4 nicotinic receptor inhibitor)
  • Trimethaphan (ganglion type receptor inhibitor)
• peripherally acting
  • Prazosin (α1 antagonist)
  • Guanethidine (Magnesium-ATPase inhibitor)
  • Indoramin (α1 antagonist)
  • Doxazosin (alpha blocker)

• Sympatholytics at the US National Library of Medicine Medical Subject Headings (MeSH)
• Template:Dorlands

Template:WikiDoc Sources