Hormons ua raws li kev sib koom ua ke sib txuas ntau yam kev tswj hwm thiab cov txheej txheem metabolic hauv lub cev. Lawv ua lub luag haujlwm ntawm cov tshuaj intermediaries uas ua kom muaj kev hloov pauv ntawm cov teeb liab uas tshwm sim hauv cov nruab nrog cev thiab hauv nruab nrab paj hlwb. Cells teb txawv rau cov tshuaj hormones.
Los ntawm adenylate cyclase system, cov ntsiab lus cuam tshuam rau tus nqi ntawm cov txheej txheem biochemical hauv lub hom phiaj ntawm tes. Xav txog qhov txheej txheem no kom ntxaws.
Physiological effect
Cov lus teb ntawm cov hlwb rau qhov kev txiav txim ntawm cov tshuaj hormones nyob ntawm nws cov qauv tshuaj, nrog rau hom cell nws cuam tshuam.
Cov tshuaj hormones hauv cov ntshav qis heev. Txhawm rau ua kom lub zog ua haujlwm ntawm cov enzyme nrog kev koom tes ntawm adenylate cyclase system, lawv yuav tsum raug lees paub thiab tom qab ntawd cuam tshuam nrog cov receptors - cov protein tshwj xeeb uas muaj qhov tshwj xeeb.
Cov nyhuv physiological yog txiav txim los ntawm ntau yam, piv txwv li, qhov concentration ntawm cov tshuaj hormones. Nws yog txiav txim los ntawm qhov ceevinactivation thaum lub sij hawm lwj, tshwm sim feem ntau nyob rau hauv lub siab, thiab tus nqi ntawm nws excretion nrog rau cov metabolites. Cov nyhuv physiological nyob ntawm qhov degree ntawm affinity ntawm cov tshuaj hormones rau carrier proteins. Cov thyroid thiab steroid cov ntsiab lus txav mus raws cov hlab ntsha ua ke nrog cov proteins. Tus naj npawb thiab hom receptors ntawm lub hom phiaj hlwb kuj txiav txim siab yam.
Cov Lus Qhia
Cov txheej txheem ntawm kev sib txuas thiab tso tawm cov tshuaj hormones yog txhawb los ntawm sab hauv thiab sab nraud impulses coj mus rau hauv nruab nrab lub paj hlwb. Neurons nqa cov teeb liab no mus rau hypothalamus. Ntawm no, vim lawv, cov synthesis ntawm statins thiab liberins (peptide tso cov tshuaj hormones) yog stimulated. Lawv, nyob rau hauv lem, inhibit (suppress) los yog txhawb lub synthesis thiab secretion ntawm cov ntsiab nyob rau hauv lub anterior pituitary caj pas. Cov tshuaj no yog hu ua triple hormones. Lawv txhawb kev tsim khoom thiab tso tawm cov ntsiab lus hauv cov qog endocrine peripheral.
Cov cim qhia ntawm cov tshuaj hormones
Zoo li lwm yam kev taw qhia lub cev, cov ntsiab lus no qhia ntau tus yam ntxwv. Hormones:
- Tawm tawm ntawm cov hlwb uas tsim tawm rau hauv qhov chaw ntxiv.
- Tsis siv los ua lub zog.
- Lawv tsis yog cov txheej txheem ntawm cov hlwb.
- Muaj peev xwm tsim kom muaj kev sib raug zoo nrog cov hlwb uas muaj cov receptors tshwj xeeb rau cov tshuaj hormones.
- Sib txawv hauv kev ua haujlwm lom neeg siab. Txawm tias nyob rau hauv me me, cov tshuaj hormones tuaj yeem cuam tshuam cov hlwb.
Tim Cells
Lawv kev cuam tshuam nrog cov tshuaj hormones yog muab los ntawm cov protein tshwj xeeb receptors. Lawv muaj nyob rau ntawm daim nyias nyias, nyob rau hauv lub cytoplasm, nyob rau hauv lub nuclear membrane thiab lwm yam organelles.
Muaj ob qhov chaw (qhov chaw) hauv ib qho receptor protein. Vim yog lawv, cov haujlwm tau ua tiav:
- Hormone lees paub.
- Kev hloov pauv thiab xa tawm ntawm qhov tau txais kev txhawb nqa mus rau lub cell.
Txheej ntawm receptors
Nyob rau hauv ib qho ntawm cov protein domains muaj ib qhov chaw uas yog complementary (muab complementary) rau tej lub caij ntawm lub teeb liab molecule. Kev khi ntawm cov receptor rau nws zoo ib yam li cov txheej txheem ntawm kev tsim cov enzyme-substrate complex thiab txiav txim siab los ntawm kev sib raug zoo tas li.
Feem ntau ntawm cov receptors tam sim no tsis nkag siab zoo. Qhov no yog vim qhov nyuaj ntawm lawv cov kev sib cais thiab kev huv, nrog rau cov ntsiab lus tsis tshua muaj siab ntawm txhua hom receptor hauv cov hlwb. Txawm li cas los xij, nws paub tias kev sib cuam tshuam ntawm cov tshuaj hormones nrog cov receptors yog ib qho physicochemical xwm. Hydrophobic thiab electrostatic bonds yog tsim los ntawm lawv.
Kev sib cuam tshuam ntawm cov tshuaj hormones thiab cov receptor yog nrog los ntawm kev hloov pauv hauv qhov kawg. Yog li ntawd, lub complex ntawm lub teeb liab molecule nrog lub receptor yog qhib. Ua nyob rau hauv ib lub xeev active, nws muaj peev xwm provoke ib tug tshwj xeeb intracellular teb rau cov khoom xa tuaj. Thaum lub synthesis los yog muaj peev xwm ntawm receptors cuam tshuam nrog signaling molecules yog impaired, kab mob tshwm sim - endocrine ntshawv siab.
Lawv tej zaum yuav cuam tshuam rau:
- Tsis muaj kev sib txuas.
- Hloov pauv hauv cov qauv ntawm cov receptor proteins (kev mob caj ces).
- Thaiv cov receptors nrog cov tshuaj tiv thaiv.
Kev sib tham hom
Lawv txawv nyob ntawm tus qauv ntawm cov tshuaj hormone molecule. Yog hais tias nws yog lipophilic, nws muaj peev xwm nkag mus rau lipid txheej nyob rau hauv lub txheej membrane ntawm lub hom phiaj. Ib qho piv txwv yog steroid hormones. Yog tias qhov loj ntawm cov molecule tseem ceeb, nws tsis tuaj yeem nkag mus rau hauv lub cell. Raws li, receptors rau lipophilic cov tshuaj hormones nyob rau hauv lub hom phiaj, thiab rau hydrophilic cov tshuaj hormones - sab nraud, nyob rau hauv daim nyias nyias.
Second intermediaries
Tau txais cov lus teb rau cov teeb liab hormonal los ntawm hydrophilic molecules yog muab los ntawm intracellular mechanism ntawm impulse kis tau tus mob. Nws ua haujlwm los ntawm qhov hu ua thib ob intermediaries. Hauv qhov sib piv, cov tshuaj hormones molecules muaj ntau yam hauv lawv cov duab.
Cyclic nucleotides (cGMP thiab cAMP), calmodulin (calcium-binding protein), calcium ions, inositol triphosphate, enzymes koom nrog hauv kev sib txuas ntawm cyclic nucleotides thiab protein phosphorylation ua "tus xa xov thib ob".
Kev ua ntawm cov tshuaj hormones los ntawm adenylate cyclase system
Muaj 2 txoj hauv kev tseem ceeb los xa ib qho kev xav rau lub hlwb los ntawm cov teeb liab:
- Adenylate ceclase (guanylate cyclase) system.
YPhosphoinositide mechanism.
Cov txheej txheem ntawm kev ua ntawm cov tshuaj hormones los ntawm adenylate cyclase system suav nrog: G protein, protein kinases,receptor protein, guanosine triphosphate, adenylate ceclase enzyme. Ntxiv nrog rau cov tshuaj no, ATP kuj tseem tsim nyog rau kev ua haujlwm ntawm lub cev.
Receptor, G protein, nyob ze qhov twg GTP thiab adenylate cyclase nyob, tau tsim rau hauv cov cell membrane. Cov ntsiab lus no nyob rau hauv lub xeev dissociated. Tom qab tsim cov complex ntawm lub teeb liab molecule thiab receptor protein, conformation ntawm G protein hloov. Yog li ntawd, ib qho ntawm nws cov subunits tau txais lub peev xwm los cuam tshuam nrog GTP.
Cov tsim complex "G protein + GTP" ua kom adenylate cyclase. Nws, nyob rau hauv lem, pib hloov ATP molecules rau hauv cAMP. Nws muaj peev xwm ua kom cov enzymes tshwj xeeb - protein kinases. Vim li no, cov tshuaj tiv thaiv ntawm phosphorylation ntawm ntau cov protein molecules nrog kev koom tes ntawm ATP yog catalyzed. Cov muaj pes tsawg leeg ntawm cov protein nyob rau tib lub sijhawm suav nrog cov seem ntawm phosphoric acid.
Vim lub tshuab ua haujlwm ntawm cov tshuaj hormones hauv adenylate cyclase system, kev ua haujlwm ntawm phosphorylated protein hloov. Hauv ntau hom hlwb, cov proteins ntawm kev ua haujlwm sib txawv tau cuam tshuam: nuclear lossis membrane molecules, nrog rau cov enzymes. Raws li qhov tshwm sim ntawm phosphorylation, cov proteins tuaj yeem ua haujlwm tsis zoo lossis tsis ua haujlwm.
Adenylate cyclase system: biochemistry
Vim qhov kev sib cuam tshuam tau piav qhia saum toj no, tus nqi ntawm cov txheej txheem biochemical hauv lub hom phiaj hloov pauv.
Nws yog qhov tsim nyog los hais txog lub sijhawm tsis tseem ceeb ntawm kev ua kom lub cev adenylate cyclase. Lub brevity yog vim qhov tseeb tias G protein, tom qab khi rau lub enzymeKev ua GTPase pib tshwm. Nws rov qab ua raws li GTP hydrolysis thiab tsis ua rau adenylate cyclase. Qhov no ua rau kev txiav tawm ntawm cov tshuaj tiv thaiv cAMP.
Kev txwv tsis pub
Ntxiv rau cov neeg koom ncaj qha hauv cov tswv yim ntawm adenylate cyclase system, hauv qee lub hom phiaj muaj cov receptors cuam tshuam nrog G molecules, ua rau inhibition ntawm enzyme. Adenylaceteclase yog inhibited los ntawm "GTP + G protein" complex.
Thaum cAMP ntau lawm nres, phosphorylation tsis nres tam sim. Ntev npaum li cov molecules muaj nyob, kev ua kom cov protein kinases yuav txuas ntxiv mus. Txhawm rau nres qhov kev txiav txim ntawm cAMP, hlwb siv cov enzyme tshwj xeeb - phosphodiesterase. Nws catalyses cov hydrolysis ntawm 3', 5'-cyclo-AMP rau AMP.
Qee lub tebchaw uas muaj cov nyhuv inhibitory ntawm phosphodiesterase (piv txwv li, theophylline, caffeine) pab tswj thiab ua kom cov concentration ntawm cyclo-AMP. Raws li kev cuam tshuam ntawm cov tshuaj no, lub sijhawm ua haujlwm ntawm adenylate cyclase messenger system. Hauv lwm lo lus, qhov kev txiav txim ntawm cov tshuaj hormone yog txhim kho.
YInositol triphosphate
Dhau li ntawm adenylate cyclase signal transduction system, muaj lwm lub teeb liab hloov tshuab. Nws suav nrog calcium ions thiab inositol triphosphate. Cov tom kawg yog ib yam khoom muab tau los ntawm inositol phosphatide (ib qho lipid complex).
Inositol triphosphate yog tsim los ntawm phospholipase "C", ib qho tshwj xeeb enzyme uas tau qhib thaum lub sij hawm hloov pauv hauv lub hauv nruab nrog cev.cell membrane receptor.
Vim qhov kev ua ntawm cov enzyme no, phosphoester daim ntawv cog lus ntawm phosphatidyl-inositol-4,5-bisphosphate molecule yog hydrolyzed. Yog li ntawd, inositol triphosphate thiab diacylglycerol yog tsim. Lawv tsim ua, nyob rau hauv lem, nce nyob rau hauv cov ntsiab lus ntawm ionized calcium nyob rau hauv lub cell. Qhov no pab txhawb rau kev ua kom muaj ntau yam calcium-dependent protein molecules, nrog rau cov protein kinases.
Nyob rau hauv rooj plaub no, ib yam li lub community launch ntawm adenylate cyclase system, protein phosphorylation ua raws li ib tug ntawm cov theem ntawm impulse kis tau tus mob nyob rau hauv lub cell. Nws ua rau cov lus teb ntawm lub cev ntawm tes rau cov nyhuv ntawm cov tshuaj hormone.
Txoj kev sib txuas
Ib qho protein tshwj xeeb, calmodulin, koom nrog hauv kev ua haujlwm ntawm phosphoinositide mechanism. Ib feem peb ntawm nws cov muaj pes tsawg leeg yog tsim los ntawm cov amino acids tsis zoo (Asp, Glu). Hauv qhov no, nws muaj peev xwm txuas tau Ca+2.
Muaj 4 qhov chaw sib khi hauv ib qho tshuaj maj mam ua kom zoo. Raws li qhov tshwm sim ntawm kev sib cuam tshuam nrog Ca + 2, kev hloov pauv hloov pauv pib hauv cov tshuaj calmodulin molecule. Raws li qhov tshwm sim, Ca + 2-calmodulin complex tau txais lub peev xwm los tswj cov haujlwm ntawm ntau cov enzymes: phosphodiesterase, adenylate cyclase, Ca + 2, Mg + 2 - ATPase, nrog rau ntau yam protein kinases.
Nuances
Hauv cov hlwb sib txawv, nyob rau hauv kev cuam tshuam ntawm Ca + 2-calmodulin complex ntawm isoenzymes ntawm ib qho enzyme (piv txwv li, ntawm adenylate cyclase ntawm ntau hom), nyob rau hauv ib rooj plaub ua kom pom, thiab lwm yam. - inhibition ntawm cAMP tsim. Qhov no yog vim qhov tseeb tias allosteric chaw hauv isoenzymestuaj yeem suav nrog ntau cov amino acid radicals. Raws li, lawv cov tshuaj tiv thaiv rau qhov cuam tshuam ntawm txoj kev yuav txawv.
Extra
Raws li koj tuaj yeem pom, "tus xa xov thib ob" tau koom nrog hauv adenylate cyclase system thiab hauv cov txheej txheem tau piav qhia saum toj no. Thaum phosphoinositide mechanism ua haujlwm, lawv yog:
YCyclic nucleotides. Raws li nyob rau hauv lub adenylate cyclase system, lawv yog c-GMP thiab c-AMP.
YCalcium ions.
YDiacylglycerol.
Y
Cov txheej txheem ntawm kev taw qhia los ntawm cov tshuaj hormone molecules nyob rau hauv cov hom phiaj uas cuam tshuam nrog cov neeg nruab nrab saum toj no muaj ntau yam nta:
- Ib theem ntawm kev hloov ntaub ntawv yog cov txheej txheem ntawm cov protein phosphorylation.
- Kev ua kom tsis txhob raug cuam tshuam los ntawm cov txheej txheem tshwj xeeb. Lawv tau pib los ntawm cov txheej txheem koom nrog lawv tus kheej (hauv qab kev cuam tshuam ntawm cov tswv yim tsis zoo).
Zoo kawg
Hormones ua raws li lub ntsiab lus humoral regulators ntawm physiological functions nyob rau hauv lub cev. Lawv tsim nyob rau hauv cov qog endocrine los yog tsim los ntawm cov kab mob endocrine tshwj xeeb. Cov tshuaj hormones raug tso tawm rau hauv cov qog ntshav, ntshav thiab muaj qhov cuam tshuam (endocrine) ntawm cov hlwb.
Tam sim no, cov khoom ntawm cov moleculeszoo txaus kawm. Cov txheej txheem ntawm lawv cov biosynthesis paub, nrog rau cov txheej txheem tseem ceeb ntawm lub cev. Txawm li cas los xij, tseem muaj ntau yam tsis paub daws teeb meem ntsig txog qhov peculiarities ntawm kev sib cuam tshuam ntawm cov tshuaj hormones thiab lwm yam sib txuas.
