Kodi kapangidwe ka cholesterol m'chiwindi chimakhala bwanji?

Popeza mankhwalawo ndi a gulu la ma alcohols, mawu akuti "cholesterol" ndi okhawo ovomerezeka, pomwe dzina loti "cholesterol" (kwenikweni "ngumu yolimba" chifukwa chodzipatula koyambirira kwa miyala yamtengo wapatali) linaperekedwa koyamba mu 1769 ndi fayilo wa ku France Pouletier de La Sal, adawonetsa mawonekedwe enieni a mafuta, komwe adayikidwa pachiyambipo.

Chifukwa cha zolakwa zina zakusaka kwa asayansi, cholesterol idalembedwa kuti "mdani Na. 1" thanzi la thupi kwazaka zambiri, zomwe zidapangitsa kusinthika kwenikweni mumakampani azakudya, pharmacology ndi njira zamankhwala - kuphatikiza ndi zinthu zamafuta ochepa, mankhwala atsopano ndi njira zomwe zidawonekera mdziko lapansi zomwe zitha kuchepetsa kwambiri kusagwedezeka amaphatikizika m'magazi, ndi zonse izi - ndi zida zowongolera za "tizilombo" kuti nthawi zonse ziziyang'anira.

Popeza njira yabwino yodziwonera kuvulaza kwa chinthu chimodzi kapena china ndi njira yochotsera kuzungulira, izi zachitika - chifukwa chake, dziko lonse lapansi likututa zipatso zoyipa za "zakudya zowononga", ndipo asayansi amakakamizika kupereka zifukwa zakulonjeza kuti adzazikonza. Koma izi zitha kuchitika pongomvetsetsa komwe kumachokera komanso tanthauzo lenileni la chinthu m'thupi.

Ntchito zazikuluzikulu za cholesterol

Kuphatikiza apo ndikuti ndi gawo lofunikira (fluidity stabilizer) ya cytoplasmic membrane, kuonetsetsa kukhazikika kwake kawiri chifukwa chogwirana kwambiri ndi mamolekyu a phospholipid, cholesterol imadziwonetsera yokha ngati gawo loyang'anira kuchuluka kwa maselo a cell, kuletsa magazi kupindika kwa hemolrate. .

Imathandizanso ngati choyambira pakupanga mankhwala opangira gulu la steroid:

• mahomoni a corticosteroid;
• mahomoni ogonana;
• bile zidulo;
• Mavitamini a gulu la D (ergocalciferorol ndi cholecalciferol).

Poganizira kufunika kwa gawo lirilonse la zinthuzi, zimawonekeratu kuvulaza kwa zakudya zopanda mafuta a cholesterol kapena kuchepa kwaposachedwa koyipa kwa chinthu ichi m'magazi.

Chifukwa chosakhazikika m'madzi, chinthuchi chimatha kunyamulidwa ndi magazi kokha molumikizana ndi mapuloteni otulutsa (apolipoproteins), akaphatikizidwa ndi omwe ma lipoprotein amapangidwa.

Chifukwa cha kupezeka kwa ma apolipoproteins angapo (kusiyana ndi kulemera kwa maselo, kuchuluka kwawo kwa cholesterol, komanso chifukwa cha kupangika kwa kuphatikizika kwa magazi, komanso zinthu zosagwirizana ndi mafuta a cholesterol makhwala a mapangidwe a atherosranceotic), magulu otsatirawa a lipoproteins amadziwika.

• kuchuluka kwambiri (HDL, kapena kulemera kwakukulu, kapena HDL-lipoproteins);
• kachulukidwe kakang'ono (LDL, kapena kuchepa kwamankhwala ocheperako, kapena LDL-lipoproteins);
• kachulukidwe kotsika kwambiri (VLDL, kulemera kotsika kwambiri, kapena gulu la VLDL la lipoproteins);
• ma chylomicrons.

Kwa zotumphukira zakumapeto, cholesterol imalowetsedwa ku ma chylomicrons, LDL kapena VLDL, kupita ku chiwindi (ndikuchotsa pambuyo pake m'thupi) - ponyamula ma apolipoproteins a gulu la HDL.

Mawonekedwe

Kuti malo ena atherosulinotic apangidwe kuchokera ku cholesterol (yomwe nthawi yomweyo imadzakhala "zigamba" pakhoma lowonongeka, ndi "ma spacers" am'deralo komwe popanda iwo kuwonongeka kwa minofu kumayambitsa kutsika kwake - malowo amagwa, kapena mahomoni, kapena zinthu zina, ziyenera kupangidwa m'thupi m'malo amodzi:

• khungu
• matumbo;
• chiwindi.

Popeza ma cell a chiwindi (cytosol yawo ndi yosalala endoplasmic reticulum) ndi omwe amapereka othandizira pawiri (mu 50% kapena kuposa), kapangidwe kazinthuzo kamayenera kuganiziridwa ndendende kuchokera kumbali ya momwe zimachitikira zimachitikira.

Kuphatikizika kwa cholesterol kumachitika mu magawo asanu - ndi kupangika kotsatizana:

• mevalonate;
• isopentenyl pyrophosphate;
• squalene;
• lanosterol;
• kwenikweni cholesterol.

Zosintha zingapo sizingatheke popanda gawo la michere yomwe imapangitsa gawo lililonse la njirayi.

Kanema pa kapangidwe ka cholesterol:

Enzymes nawo ntchito yokhudza kupangidwa kwa nkhani

Pa gawo loyamba (lokhala ndi magwiridwe atatu), kupangidwa kwa acetoacetyl-CoA (apa CoA - coenzyme A) imayambitsidwa ndi acetyl-CoA-acetyltrasferase (thiolase) mwa kuphatikiza mamolekyulu a 2 acetyl-CoA. Kuphatikiza apo, kutenga nawo gawo kwa HMG-CoA synthase (hydroxymethyl-glutaryl-CoA synthase), kaphatikizidwe kuchokera ku acetoacetyl-CoA ndi molekyulu ina ya acetyl-CoA ꞵ-hydroxy-ꞵ-methylglutaryl-CoA itheka.

Pambuyo pakuchepetsa kwa HMG (ꞵ-hydroxy-ꞵ-methyl-glutaryl-CoA) ndi kufalikira kwa chidutswa cha HS-CoA ndikuchita nawo gawo la NADP-hydroxymethyl-glutaryl-CoA reductase (HMG-CoA reductase), chinthu choyambirira chapakati, kolesterol preric. )

Pa gawo la kapangidwe ka isopentinyl pyrophosphate, ntchito zinayi zimachitika. Pogwiritsa ntchito mevalonate kinase (kenako phosphomevalonate kinase), Mevalonate imasinthidwa kukhala 5-phosphomevalonate pa 1 ndi 2 Mevalonate kinase (kenako phosphomevalonate kinase), kenako mpaka 5-pyrophosphomevalonate, yomwe imakhala 3-phospho-5-pyrophosphomeation 3 at 3 phphophosphomeation 3ate. (ndi gawo la enase.

Ntchito yomalizayi ndi decarboxylation ndi dephosphorylation ndikupanga isopentinyl pyrophosphate (yoyambitsidwa ndi kutenga nawo gawo kwa enzyme pyrophosphomevalonate decarboxylase).

Mu kapangidwe ka squalene, isomerization yoyambirira ya isopentenyl pyrophosphate kuti dimethylallyl pyrophosphate imachitika (motsogozedwa ndi isopentyl phosphatisomerase), ndiye isopentenyl pyrophosphate yodzikongoletsa ndi dimethylallyl pyrophosphate (mphamvu yamagetsi imapangidwa pakati pa C₅ woyamba ndi C₅ chinthu chachiwiri) ndi kupangidwa kwa geranyl pyrophosphate (ndi cleavage wa molekyulu ya pyrophosphate).

Mu gawo lotsatira, mgwirizano pakati pa C₅ isopentenyl pyrophosphate ndi C₁₀ geranyl pyrophosphate - chifukwa cha kuvomerezedwa koyambirira ndi kwachiwiri, farnesyl pyrophosphate amapangidwa ndipo molekyulu yotsatira ya pyrophosphate imachotsedwa ku C₁₅.

Gawo ili likutha ndi kuvomerezedwa kwa mamolekyulu awiri a farnesyl pyrophosphate mu zone C₁₅- C₁₅ (pamutu mpaka pamutu) ndikuchotsa ma mamolekyulu a 2 pyrophosphate kamodzi. Povomerezeka ndi mamolekyulu onse, zigawo za magulu a pyrophosphate amagwiritsidwa ntchito, imodzi mwa yomwe imapangidwa mwachangu, zomwe zimapangitsa kuti pquophosphate apangidwe. NADPH ikakhala yafupika (ndikuchotsedwa kwa pyrophosphate yachiwiri), chinthu chapakatikati ichi (motsogozedwa ndi squalene synthase) chimasanduka skavalen.

Pali ntchito ziwiri za kapangidwe ka lanosterol: yoyamba imatha ndi kupangika kwa squalene epoxide (wothandizidwa ndi squalene epoxidase), yachiwiri - ndi cyclization ya squalene epoxide mu gawo lomaliza la siteji - lanosterol. Kusuntha gulu la methyl kuchokera ku C₁₄ pa C₁₃, komanso kuchokera ku C₈ pa C₁₄ amadziwa oxidosqualene-lanosterol cyclase.

Gawo lomaliza la kaphatikizidwe kamaphatikizidwe ka magawo asanu. Zotsatira zake makulidwe a C₁₄ Gulu la methyl la lanosterol limatulutsa gulu lotchedwa 14-desmethylanosterol. Pambuyo pochotsedwa magulu ena awiri a methyl (mu C₄) thunthu limakhala zymosterol, komanso chifukwa chakuthamangitsidwa kwa chomangira iwiri C₈= C₉ kuyika C₈= C₇ Kapangidwe ka δ-7,24-cholestadienol kumachitika (mothandizidwa ndi isomerase).

Pambuyo posuntha kawiri C₇= C₈ kuyika C₅= C₆ (ndikupanga kwa desmosterol) ndikubwezeretsa kuphatikiza kwapawiri m'mbali mwake, chinthu chomaliza chimapangidwa - cholesterol (kapena m'malo mwake, cholesterol). Enzimu ya "δ" 24-reductase "imatsogolera" gawo lotsiriza la cholesterol synthesis.

Zomwe zimakhudza mtundu wa cholesterol?

Poganizira mphamvu zochepa za lipoproteins (LDL) yocheperako, kusintha kwawo makulidwe a cholesterol (ndi mapangidwe a atherosulinosis m'mitsempha yamagazi yomwe imawonjezera zovuta zamtima ndi zotupa zam'mimba), ma lipoproteins amtunduwu amatchedwa "cholesterol" kulemera kwamankhwala (HDL) yokhala ndi katundu wotsutsana (popanda chiwopsezo cha atherogenicity) imatchedwa cholesterol "yothandiza."

Poganizira kufananirana kwa lingaliro ili (thupi silingakhale chothandiza mwanjira iliyonse kapena zovulaza), komabe, njira zikuperekedwa kwa anthu omwe ali ndi chidwi chachikulu cha mtima wamitsempha kuti ayang'anire ndikuchepetsa LDL pamlingo woyenera kwambiri.

Ndi chithunzi choposa 4.138 mmol / l, kusankha zakudya kumalimbikitsidwa kuti achepetse 3.362 (kapena kuchepera), mulingo wapamwamba 4.914 umakhala chisonyezo chakuwonetsa mankhwala kuti achepetse kudya kwawo mankhwala.

Kuwonjezeka kwa kachigawo kakang'ono ka magazi ka "cholesterol yoyipa" kumayamba chifukwa cha zifukwa:

• zolimbitsa thupi (zolimbitsa thupi);
• kudya kwambiri chakudya (kudalira chakudya), komanso zotulukapo zake - kunenepa kwambiri kapena kunenepa kwambiri;
• zakudya zosagwirizana - ndi kuchuluka kwa mafuta, ma digesti, ma muffins osokoneza bongo omwe amawononga zomwe zili ndi pectin, fiber, mavitamini, michere ya zinthu, mafuta acids a polyunsaturated zikuchokera;
• kupezeka kwa zakumwa zozizilitsa kukhosi (kusuta, kumwa mowa mwa mitundu ingapo ya zakumwa zoledzeretsa).

Kukhalapo kwa matenda amtundu wamatenda amodzi kumathandizanso.

• matenda a ndulu;
• zovuta za endocrine ndi hyperproduction ya mahomoni a adrenal cortex, kuchepa kwa chithokomiro kapena mahomoni ogonana, kapena matenda a shuga;
• aimpso ndi kwa chiwindi kusakwanira ndi kusokonezeka kwa magawo ena a kapangidwe ka lipoprotein "zothandiza" zomwe zimachitika mu ziwalo izi;
• cholowa dyslipoproteinemia.

Mkhalidwe wa cholesterol metabolism mwachindunji umadalira mkhalidwe wamatumbo microflora, omwe amalimbikitsa (kapena amaletsa) kuyamwa kwa mafuta azakudya, komanso amatenga nawo gawo pazomwe zimasinthidwa, kusinthika, kapena kuwonongeka kwa sterols a exo native kapena endo native.

Ndipo mosinthanitsa, kuti muchepetse chizindikiro cha "yoyipa" ya cholesterol:

• maphunziro akuthupi, masewera, kuvina;
• kukhalabe ndi moyo wathanzi popanda kusuta fodya komanso mowa;
• chakudya choyenera chopanda kuchuluka kwa chakudya chamagetsi chosavuta, chokhala ndi mafuta ochepa a nyama yokhala ndi zotumphukira - koma chili ndi zokwanira za fiber, polyunsaturated mafuta acids, lipotropic zinthu (lecithin, methionine, choline), kufufuza zinthu, mavitamini.

Kanema kuchokera kwa katswiri:

Kodi machitidwe ali bwanji mthupi?

Pafupifupi 20% yokha ya cholesterol yomwe imalowa m'thupi ndi chakudya chomwe imadya - imapanga 80% yotsala yokha, kuwonjezera chiwindi, kaphatikizidwe kameneka kamachitika ndi masentimita endoplasmic reticulum maselo:

• matumbo;
• adrenal gland;
• impso
• maliseche.

Kuphatikiza pa njira yakale yopangira mamolekyulu a cholesterol omwe afotokozedwa pamwambapa, ndizothekanso kuipanga pogwiritsa ntchito njira yopanda mevalonate. Chifukwa chake, imodzi mwazomwe mungasankhe ndikupanga chinthu kuchokera ku glucose (chomwe chimachitika kudzera mu ma enzymes ena komanso pansi pazinthu zina).