muscarinic

Examples of muscarinic in the following topics:

• Agonists, Antagonists, and Drugs

  • ACh binds to muscarinic receptors (M2) that are found principally on cells comprising the sinoatrial (SA) and atrioventricular (AV) nodes.
  • Muscarinic receptors are coupled to the Gi-protein; therefore, vagal activation decreases cAMP.
  • Muscarinic receptor antagonists bind to muscarinic receptors thereby preventing ACh from binding to and activating the receptor.
  • By blocking the actions of ACh, muscarinic receptor antagonists very effectively block the effects of vagal nerve activity on the heart.
  • Atropine's pharmacological effects are due to binding to muscarinic acetylcholine receptors.

• Parasympathetic Responses

  • The ACh acts on two types of receptors, the muscarinic and nicotinic cholinergic receptors.
  • The postganglionic nerve then releases ACh to stimulate the muscarinic receptors of the target organ.

• Neurotransmitters

  • The cholinergic system has two types of receptors: the nicotinic receptor and the acetylcholine receptor, which is known as the muscarinic receptor.
  • Muscarine, a chemical product of certain mushrooms, binds to the muscarinic receptor.
  • However, when acetylcholine binds to the muscarinic receptor, it might cause depolarization or hyperpolarization of the target cell.

• Cholinergic Neurons and Receptors

  • Although acetylcholine induces contraction of skeletal muscle, it acts via a different type of receptor (muscarinic, see ) to inhibit contraction of cardiac muscle fibers.
  • This human M2 muscarinic acetylcholine receptor is bound to an antagonist

• Postganglionic Neurons

  • Postganglionic neurons of sweat glands release acetylcholine for the activation of muscarinic receptors.
  • The ACh acts on two types of receptors, the muscarinic and nicotinic cholinergic receptors.
  • The postganglionic nerve then releases ACh to stimulate the muscarinic receptors of the target organ.

• Nomenclature and Structure of Amines

  • Thus, Serotonin and Thiamine are 1º-amines, Coniine is a 2º-amine, Atropine, Morphine and Quinine are 3º-amines, and Muscarine is a 4º-ammonium salt.
  • Of course, quaternary ammonium salts, such as that in muscarine, have a tetrahedral configuration that is incapable of inversion.

• Primary and Secondary Metabolites

  • Atropine is a competitive antagonist for acetycholine receptors, specifically those of the muscarinic type, which can be used in the treatment of bradycardia.

• Ionotropic and Metabotropic Receptors

  • Examples of metabotropic receptors include glutamate receptors, muscarinic acetylcholine receptors, GABAB receptors, most serotonin receptors, and receptors for norepinephrine, epinephrine, histamine, dopamine, neuropeptides, and endocannabinoids.

• Function and Physiology of the Spinal Nerves

  • In the parasympathetic system, ganglionic neurons use acetylcholine as a neurotransmitter to stimulate muscarinic receptors.