Receptorium acetylcholini muscarinicum

Receptoria acetylcholini muscarinica (mAChR) sunt receptoria acetylcholini, complexus cum proteino G copulata formantes et sub haec canales ionticos vel nuntios secundarios excitant. Locata sunt mAChR in membranis neuronorum.

Neurotransmissor acetylcholinum (ACh) est agonista naturalis receptoriorum muscarinicorum.

Muscarinum agonista ad receptoria muscarinica ab nicotinicis separanda adhibitum

Adhuc subtypi quinque, M₁ - M₅, noti sunt.

Receptoriis muscarinicis munera sunt in cerebro at, per systema nervosum autonomicum in organis diversis ut in oculo^[1], in apparatu circulatorio^[2], in apparatu digestorio^[3], in vesica urinaria^[4].

In medicina morbi cum structuris muscarinicis coniuncti ope agonistarum vel antagonistarum tractari possunt.

Acetylcholinum et receptoria acetylcholini in genere

Acetylcholinum (ACh) est substantia chemica minor, ex atomis carbonii septem constituta; massa molaris eius tantum 146.21 g/mol est. In organismis ACh virtutes neurotransmissor ostendit. Ex synapsibus cholinergicis ("praesynapticis") in fissuram synapticam emissum, ACh receptoria propria, cholinergica, nervi proximi ("postsynaptici") obsidet. Omnia receptoria in membrana cellulae invenitur, ea sunt proteina transmembranacea. Distinguitur greges duo receptoriorum acetylcholini, receptoria nicotinica et receptoria muscarinica. Effectus acetylcholini nominantur cholinergici. Substantiae, insuper receptoria acetylcholini stimulantes, cholinergicae vocantur, tales, receptoria acetylcholini inhibentes, anticholinergicae.

Natura receptoriorum muscarinicorum

Inveniuntur receptoria muscarinica in systemate nervoso centrali et in systemate nervoso autonomico^[5]. Separantur quinque receptoria M₁ - M₅ nominata, quibus omnibus septem segmenta transmembranacea, quae in parte structura helicis ostendunt, sunt. Recipiunt neurotransmissor acetylcholinum (ACh) extra cellulam; deinde intra cellulam proteinum G incitant. Receptoria M₁, M₃, M₅ cum proteino Gαq/11 (olim: Gq) coniuncta, at M₂ et M₄ cum Gαi/o (olim: Gi/Go).

Subtypi receptoriorum muscarinicorum

Adhuc subtypi quinque descripti sunt: M₁ - M₅^[6].

Receptorium M₁

Conferatur pagina principalis Receptorium acetylcholini muscarinicum M1.

Non raro receptorium M₁ (M1R) neuronale vocatur. Inveniuntur M1R in gangliis autonomicis.

Receptorium M₂

Invenitur receptorium M₂ in corde et in systemate nervoso centrali.

Receptorium M₃

Invenitur receptorium M₃ in multis organiis internis, ut in vasibus sanguineis, oculis, glandulis salivariis, pulmonibus, apparatu digestorio, vesica urinaria

Receptorium M₄

Invenitur receptorium M₄ in systemate nervoso centrali.

Receptorium M₅

Invenitur receptorium M₅ in systemate nervoso centrali.

Notae

1. Mitchelson F. (2012). "Muscarinic Receptor Agonists and Antagonists: Effects on Ocular Function". Handbook of experimental pharmacology (208): 263-98 
2. Harvey R. D. (2012). "Muscarinic Receptor Agonists and Antagonists: Effects on Cardiovascular Function". Handbook of experimental pharmacology (208): 299-316 
3. Ehlert F. J., Pak K. J., Griffin M. T. (2012). "Muscarinic Agonists and Antagonists: Effects on Gastrointestinal Function". Handbook of experimental pharmacology (208): 343-74 
4. Sellers D. J., Chess-Williams R. (2012). "Muscarinic Agonists and Antagonists: Effects on the Urinary Bladder". Handbook of experimental pharmacology (208): 375-400 
5. Haga T. (2013). "Molecular Properties of Muscarinic Acetylcholine Receptors". Proceedings of the Japan Academy. Series B 89 (6): 226-56 
6. Eglen R. M. (Iul 2006). "Muscarinic Receptor Subtypes in Neuronal and Non-Neuronal Cholinergic Function". Autonomic & autacoid pharmacology 26 (3): 219-33 

Nexus externi

• Taylor P. et Brown J. H. (1999): Basic Neurochemistry: Molecular, Cellular and Medical Aspects. 6th edition

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