Muscarinic vs Nicotinic Receptors
Nyob hauv ntau hom tsiaj, tej zaum nws yuav yog kab los yog tsiaj txhu, muaj lub paj hlwb. Yog vim li cas rau qhov tshwm sim yog kom muaj kev sib txuas ntawm ntau hom ntaub so ntswg thiab kuj teb rau sab nraud stimuli raws li. Lub paj hlwb yog tsim los ntawm paj hlwb, paj hlwb, ganglia thiab ntau lwm yam hloov pauv. Noj qee cov lus los ntawm sab hauv lossis sab nraud lub cev yog ua los ntawm receptors; qhov kawg rhiab heev uas excites paj hlwb nqa cov lus thiab ua haujlwm raws li. Ntawm ntau ntawm cov receptors, peb pom Muscarinic receptors thiab nicotinic receptors. Ob leeg cov receptors no muaj ib yam uas yog qhov tseeb tias ob leeg ua raws li Acetylcholine receptors. Nyob ntawm seb qhov kev ua haujlwm zoo li cas qee qhov sib txawv tuaj yeem pom ntawm ob lub receptors. Ob qho tib si receptors no tseem ceeb heev vim lawv tuaj yeem tswj hwm hauv kev xa tshuaj, ua raws li kev xaiv antagonists thiab agonists.
Muscarinic Receptor
Muscarinic receptors feem ntau sau tseg li mAChRs yog hom acetylcholine receptor. Raws li lub npe implies, muscarinic receptors kuj rhiab heev rau lub xub ntiag ntawm muscarine. Muscarinic receptors tuaj nyob rau hauv cov chav kawm receptor metabotropic receptors. Metabotropic receptors txhais tau hais tias lawv siv G-proteins ua lawv cov kev taw qhia. Lub receptor yog nyob rau hauv xya thaj tsam transmembrane thiab txuas nrog intracellular G-proteins ntawm sab hauv kawg. Thaum lub ligand acetylcholine los thiab khi rau receptor G-protein kawg pib nqa cov teeb liab molecular ntxiv mus rau nws qhov chaw kawg. Lub luag haujlwm tseem ceeb ntawm muscarinic receptors yog ua raws li lub ntsiab kawg-receptor stimulated los ntawm acetylcholine, uas yog tso tawm los ntawm postganglionic fibers nyob rau hauv lub paj hlwb parasympathetic.
Nicotinic Receptor
Nicotinic receptors feem ntau sau tseg ua nAChRs. Nws kuj yog ib hom acetylcholine receptor. Zoo li muscarinic receptors rhiab rau muscarine, nicotinic receptors yog rhiab heev rau nicotine. Cov chav kawm ntawm receptors uas nicotinic receptors yog hu ua ionotropic receptors. Ionotropic receptors muaj cov txheej txheem sib txawv heev piv rau cov metabotropic receptors. Cov receptors no tsis siv G-cov proteins. Lawv siv gated ion channels. Thaum lub ligand acetylcholine los yog nicotine khi rau lub rooj vag, lub ion channel qhib, tso cai rau qee yam cations (K + Na + Ca2 +) kom nthuav tawm hauv lossis tawm ntawm lub cell. Nicotinic receptors khi cov neurotransmitter acetylcholine thiab nqa ob lub luag haujlwm tseem ceeb. Ib qho yog kom depolarize cov ntshav plasma, thiab lwm qhov yog los, ncaj qha lossis tsis ncaj, tswj cov haujlwm ntawm qee cov noob thiab tso tawm cov neurotransmitters.
Qhov txawv ntawm Muscarinic thiab Nicotinic Receptors yog dab tsi?
• Muscarinic receptors yog rhiab heev rau muscarine thaum nicotinic receptors yog rhiab heev rau nicotine. Txawm li cas los xij, ob qho tib si rhiab heev rau acetylcholine.
• Muscarinic receptors yog cov receptor class metabotropic receptors, thiab nicotinic receptors yog cov receptor class ionotropic receptors.
• Muscarinic receptors siv G-proteins thiab siv cov tub txib theem nrab hauv qhov taw qhia cascade, tab sis cov nicotinic receptors tsis siv G- proteins los yog cov tub txib theem nrab hauv cov teeb liab cascade.
• Muscarinic receptors tsis ua haujlwm ntawm gated ion channels tab sis ntawm trans-membrane proteins. Nicotinic receptors ua haujlwm ntawm gated ion channels.
• Muscarinic thiab nicotinic receptors muaj nyob hauv ntau qhov chaw.
