Alpha vs Beta Receptors
Catelocholamines yog cov sympathetic neurohumodal transmitters nrog rau noradrenaline thiab dopamine. Cov tshuaj no cuam tshuam ncaj qha nrog receptors ntawm lub cell membrane thiaj li ua kom tiav lawv cov kev ua. Qhov kev sib cuam tshuam no yog ib kauj ruam tseem ceeb hauv cov txheej txheem ntawm kev ua ntawm catecholamines, uas thaum kawg coj mus rau nce lossis txo cov ntaub so ntswg hauv lub cev. Qhov nce ntawm kev ua si yog hu ua excitation, qhov txo qis yog hu ua inhibition. Xyoo 1948, Ahlquist tau npaj ob hom receptor; alpha thiab beta receptors, uas txhais tau hais tias ob qhov sib txawv ntawm cov lus teb (excitation thiab inhibition). Cov ntaub so ntswg hauv lub cev yuav muaj xws li alpha lossis beta receptors lossis ob hom receptors.
Alpha Receptors yog dab tsi?
Kev txhawb nqa ntawm alpha receptors yog feem ntau lav rau cov teebmeem excitatory ntawm catecholamines. Txawm li cas los xij, hauv qee qhov chaw, alpha receptors tuaj yeem cuam tshuam cov haujlwm. Piv txwv li; alpha receptors ntawm GI react yog inhibitory hauv kev ua. Muaj ob hom alpha receptors; alpha1 thiab alpha2 Txhua yam ntawm no muaj peb subtypes.
Alpha1 receptors feem ntau pom nyob rau hauv cov leeg nqaij leeg, uas yog excitatory hauv kev ua. Lawv ua rau constriction ntawm cov leeg nyob rau hauv cov hlab ntsha nyob rau hauv daim tawv nqaij thiab cerebral, thiab contraction ntawm pilomotor cov nqaij ntshiv ntawm daim tawv nqaij thiab radial nqaij ntawm lub iris. Lub tshuab ntawm alpha 1 yog kev hloov pauv ntawm cellular calcium ion fluxes. Alpha2 receptors feem ntau pom muaj nyob rau hauv cov ntaub so ntswg thiab ntawm cov hlab ntsha. Lub tshuab ua haujlwm ntawm alpha 2 yog qhov inhibition ntawm adenylyl cyclase.
Dab tsi yog Beta Receptors?
Beta receptors feem ntau yog lub luag haujlwm rau inhibitory ua ntawm cov ntaub so ntswg. Tab sis muaj qee qhov kev zam. Piv txwv li, cov beta receptors nyob rau hauv lub plawv yog excitatory; yog li lub luag haujlwm kom nce lub plawv dhia. Tsis tas li ntawd, beta receptors tuaj yeem ua rau muaj kev so ntawm cov leeg nqaij bronchial, hloov kev cog lus ntawm cov leeg pob txha thiab dilatation ntawm cov leeg nqaij leeg. Peb lub beta receptor subtypes yog (1) beta1 receptors ; lub luag haujlwm rau myocardial stimulation thiab renin tso tawm, (2) beta 2 receptors; lub luag haujlwm rau kev sib raug zoo ntawm cov leeg nqaij bronchial, vasodilation ntawm cov leeg pob txha thiab uterine so, thiab (3) beta 3 receptors; Lub luag haujlwm rau lipolysis ntawm adipocytes.
Qhov txawv ntawm Alpha thiab Beta Receptors yog dab tsi?
• Kev txhawb nqa ntawm alpha receptors feem ntau yog lub luag haujlwm rau cov teebmeem excitatory, whereas ntawm beta receptors yog lub luag haujlwm rau inhibitory teebmeem.
• Alpha receptors tau muab faib ntxiv rau hauv alpha1 thiab alpha2 receptors thaum beta receptors ntxiv muab faib ua beta1, beta2, thiab beta3 receptors.
• Alpha receptors feem ntau pom muaj nyob rau hauv vascular du cov leeg, cov ntaub so ntswg, thiab ntawm cov leeg neuronal, whereas beta receptors feem ntau pom muaj nyob rau hauv cov leeg nqaij bronchial, cov leeg plawv thiab cov leeg hauv plab.
