Taolo ea motsoako oa k'holeseterole

Sekemula sa karabelo ea chlesterol

2. Synthesis ea isopentenyl diphosphate. Mothating ona, masala a mararo a phosphate a entsoe ka mevalonic acid, ebe e entsoe ka decarboxylated le dehydrogenated.

3. Kamora ho kopanya limolek'hule tse tharo tsa isopentenyl diphosphate, farnesyl diphosphate e entsoe.

4. Tsela ea squalene e etsahala ha masala a mabeli a farnesyl diphosphate a tlameletsoe.

5. Kamora ts'ebetso e rarahaneng, li-squalene tse tsamaeang ka mokokotlo li hula ka leqhubu ho ea lanosterol.

6. Ho tlosoa ha lihlopha tse ngata tsa methyl, ho khutlisetsa le isomerization ea molek'hule ho lebisa ponahalong ea k'holeseterole.

Taolo ea tšebetso ea hydroxymethylglutaryl-S-CoA reductase

3. Tekanyo ea cholesterol biosynthesis le eona e ipapisitse le khatello ea maikutlo protheine e itseng e tsamaisangho fana ka ho tlama le ho tsamaisa li-metabolites tsa hydrophobic lipakeng tsa maiketsetso.

O ka botsa kapa oa tlohela maikutlo a hau.

Ntlha ea mantlha ea tsamaiso ke ts'ebetso ea ho thehoa ha mevalonic acid.

1. Melaoana ea melaoana. Cholesterol, le ka har'a sebete - le li-acid acid li thibela ho fokotsoa ha HMG-CoA.

2. Phetetso ea motsoako oa cholesterol ea HMG-CoA.

3. Taolo ea phosphorylation-dephosphorylation ea HMG-CoA reductase, foromo e sebetsang e seng phosphorylated. Glucagon e baka ho fifala, 'me insulin e baka ts'ebetso ka ts'ebetso e rarahaneng ea karabelo. Kahoo, sekhahla sa k'holeseterole ea cholesterol e fetoha ka phetoho ea ho monya le ea libaka tsa postabsorption.

4. Tekanyo ea ho fokotsoa ha phallo ea HMG-CoA ka har'a sebete e ka fetoha ka mokhoa o hlakileng oa ho feto-fetoha ha lebollo: boholo bo boholo bosiu, le bonyane hoseng.

Phapanyetsano ea estlesterol ester

Ka liseleng cholesterol esteration e etsahala ha e pepesoa acyl-CoA-cholesterol-acyltransferase (AHAT):

Acyl-CoA + Cholesterol ® NS-CoA + Acylcholesterol

Liseleng, haholo-holo linoleylcholesterol e thehiloe. Li-esters li fumanoa haholo ho cytosol e le karolo ea marotholi a lipid. Ho thehoa ha li-esters ho ka nkoa, ka lehlakoreng le leng, e le mokhoa oa ho tlosa k'holeseterole e ngata kahara litho, ka lehlakoreng le leng, e le mokhoa oa ho boloka cholesterol seleng. Ho khothaletsa libaka tsa polokelo ho etsahala ka ho nka karolo ha li-enzyme esterasehydrolyzing cholesterol esters:

Acylcholesterol + N₂O ® Fatty Acid + Cholesterol

Khopolo le hydrolysis ea li-esters e sebetsa ka ho khetheha liseleng tsa adrenal cortex.

Ho lipoprotein tsa mali Ho etsoa hoa ester ho etsahala le ho nka karolo ha lecithin-cholesterol-acyltransferase (LHAT), e ferekanyang phetisetso ea masala a acyl ho tloha lecithin ho ea k'holeseterole. LHAT e thehoa ka har'a sebete, e kenelletsoeng maling le ho kenngoa lipoprotein. LHAT e sebetsang ka ho fetisisa ho HDL, moo e fumanehang sebakeng se ka holimo. Li-cholesterol esters tse entsoeng mona ke hydrophobic hape li kenelletse mokokotlong oa lipid. Ka phospholipid monolayer, ho na le sebaka sa mahala sa cholesterol, se ka tlatsitsoeng ka cholesterol e tsoang liseleng tsa cell kapa lipoprotein tse ling. Kahoo, HDL e bonahala e le sefi sa cholesterol ka lebaka la ketso ea LHAT.

Bile Acid Synthesis

Sebeteng, karolo ea k'holeseterole e fetoha acid acid. Li-acid tsa bile li ka nkoa e le tse tsoang ho cholanic acid. Cholanic acid e joalo ha e bopehe 'meleng. Ho hepatocytes e tsoang k'holeseterole, ho thehoa li-acid tsa mantlha - chenodeoxycholic le cholic. Kamora hore secretion ea bile e kenngoe ka popelong ka tlasa ts'ebetso ea li-enzyme tsa mala a ka mpeng, ho thehiloe li-asidi tse tsoang ho tsona - lithologic le deoxycholic. Li nkuoa ho tsoa mala, ka mali a mothapo o kenang kahare, a kena ka har'a sebete, ebe a kenella ka har'a bile. Bile e na le li-acid tse kopantsoeng haholo, i.e., likhomphutha tsa tsona le glycine kapa taurine. Ho kopana ha li-acid acid ho bile ke hoo e ka bang 1%.

Karolo e ka sehloohong ea li-acid acid e ameha ho hepatoenteric circulation.Karolo e nyane ea li-acid acid - e ka bang 0.5 g ka letsatsi - e tšeloa mantle. Sena se koaelitsoe ke motsoako oa li-acid tse ncha sebeteng, letlole la bile acid le ntlafatsoa ka matsatsi a ka bang 10.

Cholesterol e boetse e hloekisoa haholo-holo ka mala. E kena ka mpeng ka lijo le ho tsoa ho sebete e le karolo ea bile. Cholesterol e kenngoeng maling e na le karoloana e tsoang ho bile (endo native cholesterolsynthesized ka har'a sebete), le karoloana e nkiloeng lijong (kholeseterole e kantle) Ho tlosa k'holeseterole ho tsoa linthong tse ling ke ha e hlahisa oxidation ho li-acid tse teng ka har'a sebete, e lateloe ke ho tlotsoa ha eona ka mouoane (hoo e ka bang 0.5 g ka letsatsi) le ka ho pepesetsoa ha k'holeseterole e sa fetoheng (hape le makhopho).

Boemong ba ho ema:

(Cholesterol_qetela + Cholesterol_ex) - (Cholesterol_qhekella + Li-acid tse tsoang_qhekella) = 0

Haeba tekano ena e tšoenyeha, khatello ea cholesterol liseleng le maling li ea fetoha. K'holeseterole e eketsehileng ea mali - hypercholesterolemia. Sena se eketsa menyetla ea lefu la atherosclerosis le lefu la gallstone.

PUSELETSO LIPID EXCHANGE

Lipid metabolism e laoloa ke tsamaiso ea methapo e bohareng. E tšoarella nako e telele khatello e mpe ea maikutlo, keketseho ea ho lokolloa ha catecholamine maling a ka baka tahlehelo e boima ea mmele. Ketso glucagon ho sistimi ea lipolytic e ts'oana le ketso ea li-catecholamines.

Adrenaline le norepinephrine eketsa ts'ebetso ea tishu ea lipase le tekanyo ea lipolysis ho lithane tsa adipose, ka lebaka leo, litaba tsa mafura a acid e plasma ea mali lia eketseha.

Insulin e na le litlamorao tse fapaneng tsa adrenaline le glucagon ho lipolysis le ho hlohlelletsa acid e mafura.

Hormone e holang e tsosa lipolysis, e tsitlallela ho kopanya ha cymblate cyclase. Pituitary hypofunction e lebisa ho ho beoa hoa mafura 'meleng (botenya ba pituitary).

Thyroxine, lihormone tsa thobalanohape ho ama metabolism ea lipid. Ho tlosoa ha litšoelesa tsa thobalano liphoofolong ho baka mafura a mangata.

LIPIDI METABOLIC KEKETSO

Cholesterol ke steroid e ikhethang ho libopuoa tsa liphoofolo. Sebaka sa mantlha sa sebopeho sa eona 'meleng oa motho ke sebete, moo 50% ea k'holeseterole e hlophisitsoeng, 15-20% e thehoa ka mpeng e nyane, tse ling kaofela li entsoe ka letlalo, adrenal cortex le gonads. Mehloli ea sebopeho sa letlole la k'holeseterole le mekhoa ea litšenyehelo li hlahisitsoe ho sa feiga. 22.1.

Sa feiga. 22.1. Ho thehwa le ho tsamaisoa ha k'holeseterole 'meleng.

K'holeseterole ea 'mele oa motho (ka kakaretso e ka bang 140 g) e ka aroloa ka lipompo tse tharo:

30 g), e fetohang ka potlako, e na le k'holeseterole ea lebota la mala, plasma ea mali, sebete le litho tse ling tsa parenchymal, nchafalo e etsahala matsatsing a 30 (1 g / ka letsatsi),

50 g), butle-butle ho fetola k'holeseterole ea litho tse ling le lisele,

60 g), k'holeseterole e nyane haholo ea lesapo la mokokotlo le bokong, lithane tse sebetsanang, sekhahla sa ntlafatso se baloa ka lilemo.

Motsoako oa cholesterol o hlaha ho cytosol ea lisele. Ena ke e 'ngoe ea litsela tse telele ka ho fetisisa tsa metabolic' meleng oa motho. E tsoela pele ka mekhahlelo e meraro: ea pele e fela ka ho etsoa ha mevalonic acid, ea bobeli e entsoe ka squalene (sebopeho sa hydrocarbon se nang le liathomo tse 30 tsa khabone). Karolong ea boraro, squalene e fetoloa molek'hule ea lanosterol, joale ho na le liphetoho tse 20 tse latellanang tse fetolelang lanosterol ho cholesterol.

Liseleng tse ling, sehlopha sa hydroxyl sa cholesterol se ikemisetsa ho theha esters. Karabelo e ts'oaroa ke enzyme ea intracellular AHAT (acylCoA: cholesterol acyltransferase). Karabelo ea esteration e boetse e hlaha maling maling a HDL, moo enzyme LHAT (lecithin: cholesterol acyltransferase) e leng teng. Li-esters tsa cholesterol ke mofuta oo ka oona o tsamaisoang ke mali kapa o kentsoe ka liseleng. Maling, hoo e ka bang 75% ea cholesterol e ka sebopeho sa esters.

Cholesterol synthesis e laoloa ke ho ama ts'ebetso le boholo ba enzyme ea bohlokoa ea ts'ebetso - 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase).

Sena se fihlella ka litsela tse peli:

1. Phosphorylation / dephosphorylation ea HMG-CoA reductase. Insulin e ntlafatsa dephosphorylation ea HMG-CoA reductase, ka hona e e fetolela boemong bo sebetsang. Ka hona, nakong ea ho monya, motsoako oa k'holeseterole oa eketseha. Nakong ena, ho ba teng ha substrate e qalang ea synthesis, acetyl-CoA, le eona ea eketseha. Glucagon e na le litlamorao tse fapaneng: ka protheine kinase A, e hlohlelletsa phosphorylation ea HMG-CoA reductase, e e fetola boemo bo sa sebetseng. Ka lebaka leo, motsoako oa k'holeseterole nakong ea postabsorption le nakong ea ho itima lijo e thibetsoe.

2. Thibelo ea ho hlophisoa ha HMG-CoA reductase.Cholesterol (sehlahisoa sa ho qetela sa tsela ea metabolic) e fokotsa sekhahla sa phetisetso ea mofuta oa HMG-CoA reductase, ka hona e thibela tlhahiso ea eona, mme li-acid acid le tsona li baka phello e tšoanang.

Ho tsamaisoa ha cholesterol ea mali ho etsoa e le karolo ea lithethefatsi. LPs e fana ka k'holeseterole ea kantle ho lisele, ho khetholla phallo ea eona lipakeng tsa litho le tlhahiso ea mmele. K'holeseterole e nang le tlhaho e isoa ho sebete e le karolo ea chM e setseng. Moo, hammoho le k'holeseterole e tsoakiloeng, e bopa letlole le tloaelehileng. Ho li-hepatocytes, li-TAG le cholesterol li kentsoe VLDL, 'me ka sebopeho sena li tšeloa maling. Tlas'a tšusumetso ea LP-lipase, hydrolyzing TAG ho glycerol le mafura acid maling, li-VLDLPs li qala ho fetoloa LSPPs ebe li LDLPs tse nang le 55% ea cholesterol le li-esters tsa eona. LDL ke eona mofuta o ka sehloohong oa k'holeseterole eo ho eona e fetisetsoang ho lisele (70% ea cholesterol 'me mali a eona maling ke karolo ea LDL). LDL e tsoang maling e kena ka har'a sebete (ho fihla ho 75%) le lisele tse ling tse nang le li-receptor tsa LDL holim'a tsona.

Haeba palo ea k'holeseterole e kenang ka seleng e feta tlhoko ea eona, moelelo oa li-receptor tsa LDL o hatelletsoe, o fokotsang phallo ea cholesterol maling. Ka ho fokotseha hoa khatello ea cholesterol ea mahala seleng, ho fapana le hoo, motsoako oa li-receptor o kenngoe tšebetsong. Li-Hormone li kenella taolong ea motsoako oa li-receptor tsa LDL: li-insulin, triiodothyronine le lihormone tsa thobalano li eketsa sebopeho sa li-receptors, mme li-glucocorticoids li fokotseha.

Ho seo ho thoeng ke "cholesterol Return Transport", i.e. tsela e netefatsang ho khutla ha cholesterol ho sebete, HDL e bapala karolo ea mantlha. Li entsoe ka har'a sebete ka mokhoa oa likhakanyo tsa pelehi tse senang cholesterol le TAG. Li-preigors tsa HDL maling li tletse ka cholesterol, li e amohela ho LPs tse ling le li-membrane tsa sele. Ho fetisoa ha cholesterol ho HDL ho kenyelletsa enzyme ea LHAT e holim 'a bona. Enzyme ena e sebelisa masala a mafura a tsoang phosphatidylcholine (lecithin) ho ea k'holeseterole. Ka lebaka leo, ho etsoa molek'hule oa hydrophobic oa cholesterol ester, o tsamaeang ka hare ho HDL. Kahoo, ha e sa tahoa HDL, e ruisitsoeng ka k'holeseterole, e fetoha HDL 3 - dikarolo tse holileng le tse kholo. HDL 3 fapanyetsana li-cholesterol esters tsa TAG tse ho VLDL le STD ka ho nka karolo ha protheine e itseng e fetisang li-cholesterol esters pakeng tsa lipoprotein. Tabeng ena, HDL 3 fetoha HDL2, boholo ba eona bo eketsehang ka lebaka la ho bokellana ha TAG. VLDL le STDL tlasa tšusumetso ea LP-lipase li fetoloa hore e be LDL, eo haholo-holo e hlahisang cholesterol ho sebete. Karolo e nyane ea cholesterol e fanoa ho sebete sa HDL2 le HDL.

Synthesis ea bile acid. Sebeteng, 500-700 mg ea bile acids ka letsatsi e entsoe ka k'holeseterole. Sebopeho sa bona se kenyelletsa ho arabela ha ho hlahisoa ha lihlopha tsa hydroxyl ka ho nka karolo ha li-hydroxylases le karabelo ea karolo e nyane ea oxidation ea lehlakore ketane ea cholesterol (sa feiga. 22.2):

Sa feiga. 22.2. Morero oa sebopeho sa li-acid acid.

Karabelo ea pele ea pele - sebopeho sa 7-a-hydroxycholesterol - se laoloa. Ts'ebetso ea enzyme e thusang karabelo ena e sitisoa ke sehlahisoa sa ho qetela sa tsela, bile asiti. Mokhoa o mong oa tsamaiso ke phosphorylation / dephosphorylation ea enzyme (sebopeho sa phosphorylated sa 7-a-hydroxylase se sebetsa). Molao o oa khonahala ka ho fetola palo ea enzyme: cholesterol e etsa hore mofuta oa 7-a-hydroxylase, le khatello ea acid ea bile. Lihormone tsa qoqotho li etsa hore ho be le 7-a-hydroxylase le khatello ea estrogen. Kameho e joalo ea estrogen ho motsoako oa li-acid acid e hlalosa hore na hobaneng lefu la gallstone le hlaha ho basali makhetlo a 3-4 ho feta ho banna.

Li-acid tsa Cholic le chenodeoxycholic tse tsoang cholesterol li bitsoa "li-acid acid tsa mantlha". Bongata ba li-acid tsena bo kopana le ho eketsoa ha lisele tsa glycine kapa taurine ho sehlopha sa carboxyl sa bile acid. Khokahano e qala ka sebopeho sa mofuta o sebetsang oa li-acids tsa acid - tse tsoang ho CoA, joale taurine kapa glycine li hokeletsoe, 'me ka lebaka leo mefuta e 4 ea li-conjugates e thehoa: taurocholic le taurohenodeoxycholic, glycocholic le glycohenodeoxycholic acid. Li emulsifiers tse matla haholo ho feta li-acid tsa pele. Li-Conjugates tse nang le glycine li thehoa makhetlo a 3 ho feta ka taurine, kaha palo ea taurine 'meleng e lekantsoe. Ka ka mpeng, palo e nyane ea li-conjugates tsa li-acid tsa mantlha tlasa ts'ebetso ea li-enzyme tsa baktheria li fetoloa hore li be le li-asidi tse ling tsa morao. Deoxycholic acid, e thehiloeng ho cholic, le lithocholic, e thehiloeng ho tloha deoxycholic, ha e qhibilihe habonolo ebile e kenella butle ka mpeng ea mala.

Hoo e ka bang 95% ea li-acid tse kenang ka mpeng li khutlela ka har'a sebete ka mothapong oa portal, ebe li boetse li bolokoa kahare ebe li sebelisoa hape emulsification ea mafura. Tsela ena ea li-acid acid e bitsoa ho potoloha ha li-enterohepatic. Ka makhopho, li-acid tsa bobeli li tlosoa hangata.

Lefu la Gallstone (cholelithiasis) ke ts'ebetso ea methapo eo majoe a bang le eona ka gallbladder, eo motheo oa eona e leng cholesterol.

Ho lokolloa ha k'holeseterole ka bile ho lokela ho tsamaisana le tokollo e lekanang ea li-acid acid le phospholipids tse bolokang limolek'hule tsa hydrophobic cholesterol maemong a micellar. Mabaka a lebisang phetohong ea karolelano ea li-acid acid le cholesterol ho bile ke: lijo tse nang le k'holeseterole e ngata, phepo e phahameng ea khalori, ho ferekana ha potoloho ea gallbladder, ho senyeha ha enterohepatic circular, ho senyeha ha litaba tsa bile acid, ts'oaetso ea gallbladder.

Ho bakuli ba bangata ba nang le cholelithiasis, mofuta oa k'holeseterole o eketsehile, 'me motsoako oa li-acid acid o tsoa ho eona o fokotseha, e leng se lebisang ho palo e nyane ea cholesterol le li-acid acid tse tsoang ka har'a lera. Ka lebaka leo, k'holeseterole e qala ho hlohlorella ka lehalung, e ba sethala sa viscous se thatafalang butle butle. Ka linako tse ling e kenngoa ka bilirubin, liprotheine le letsoai la calcium. Majoe a ka ba le cholesterol feela (majoe a cholesterol) kapa motsoako oa k'holeseterole, bilirubin, liprotheine le calcium. Majoe a chokosterol hangata a tšoeu, 'me majoe a tsoakaneng a sootho ka mebala e fapaneng.

Boemong ba pele ba ho etsoa ha majoe, chenodeoxycholic acid e ka sebelisoa e le moriana. Ha e se e le ka hara gallbladder, e qhibilihisa majoe a cholesterol, empa ke ketso e liehang ho nka likhoeli tse 'maloa.

Atherossteosis ke lefu le khetholloang ke ponahalo ea liathomo tsa atherogenic bokaholimo ba lebota la methapo. Le leng la mabaka a mantlha a ntlafatso ea ts'ebetso ea ts'oaetso ea lefu lena ke tlolo ea tekano lipakeng tsa ho ja k'holeseterole ho tsoa lijong, ho hlaha ha eona le tšilafalo e tsoang 'meleng. Bakuli ba atherosclerosis ba phahamisitse likhahla tsa LDL le VLDL. Ho na le kamano e fapaneng pakeng tsa khatello ea HDL le menyetla ea ho holisoa ke atherosclerosis. Sena se lumellana le mohopolo oa ts'ebetso ea LDL e le bakuli ba k'holeseterole liseleng, le HDL ho tsoa liseleng.

"Ntho ea mantlha" ea "metabolism" ea nts'etsopele ea atherosulinosis ke hypercholesterolemia. (cholesterol e phahameng maling).

Hypercholesterolemia e hlaha:

1. Ka lebaka la ho ja k'holeseterole e ngata, lik'habohaedreite le mafura,

2. ponelopele ea liphatsa tsa lefutso e kenyang bofokoli ba lefutso ka sebopeho sa LDL kapa li-receptors tsa tengB-100, hammoho le keketseho e atileng kapa secretion ea apoB-100 (moo ho amanang le hyperlipidemia ea lelapa, eo ho eona ho tsejoang ka mali le k'holeseterole le TAG.

Karolo ea bohlokoa mekhoeng ea ntlafatso ea atherosclerosis e bapaloa ke ho fetoloa ha moriana. Liphetoho sebopeho se tloaelehileng sa lipids le liprotheine ho LDL li etsa hore li be ntle le 'mele kahoo li ka fumaneha habonolo ke li-phagocytes.

Phetoho ea lithethefatsi e ka hlaha ka mekhoa e mengata:

1. glycosylation ea protheine e bang teng ha tsoekere e ngata maling e eketseha,

2. phetoho ea peroxide, e lebisang phetohong ea lipids ho lipoprotein le sebopeho sa apoB-100,

3. sebopeho sa li-autoimmune complexes tsa LP-antibody (lithethefatsi tse fetotsoeng li ka baka sebopeho sa autoantibodies).

LDL e fetotsoeng e kenoa ke li-macrophages. Ts'ebetso ena ha e laoloe ke palo ea k'holeseterole e kenang, joalo ka ha e kenella ka har'a lisele ka li-receptor tse itseng, ka hona li-macrophages li tlatsitsoe ka cholesterol ebe li fetoha "lisele tse foam" tse kenang sebakeng sa subendothelial. Sena se lebisa ho bopeng matheba a lipid kapa marang-rang leboteng la methapo ea mali. Boemong bona, vasotine endothelium e ka boloka sebopeho sa eona. Ka keketseho ea palo ea lisele tsa foam, tšenyo ea endothelial e etsahala. Tšenyo e tlatsetsa ho ts'ebetsong ea liplatelete. Ka lebaka leo, li secrete thromboxane, tse eketsang kopanelo ea liplatelete, hape li qala ho hlahisa ntlha ea kholo e nkiloeng ka liplatelete, e thusang ho ata ha lisele tse boreleli tsa mesifa. Tse qetellang li tloha morafong li isa karolong e ka hare ea lebota la khale, ka hona li tlatsetsa kholo ea lejoe. Ho feta moo, lesela lena le hlaha ka lisele tsa fibrous, lisele tse ka tlasa membrane ea fibrous li necrotic, 'me k'holeseterole e behiloe sebakeng se kopaneng. Mekhahlelong ea ho qetela ea ntlafatso, pente e kenngoa ka letsoai la calcium mme e ba le letsoai haholo. Sebakeng sa lesela, methapo ea mali hangata e theha, e thibella lumen ea sekepe, e lebisang ho tsitsinyehang ho potoloha hoa mali setsing sa "lithane" le ts'ebetso ea tlhaselo ea pelo.

Taolo ea motsoako oa k'holeseterole - enzyme ea eona ea bohlokoa (HMG-CoA reductase) e etsoa ka mekhoa e fapaneng.

Phosphorylation / dephosphorylation ea Phokotso ea HMG. Ka keketseho ea karolelano ea insulin / glucagon, phosphorylates ea enzyme mme e fetela boemong bo sebetsang. Ketso ea insulin e etsoa ka li-enzyme tse peli.

HMG-CoA reductase kinase phosphatase, e fetolang kinase hore e be boemo bo sa sebetseng ba dephosphorylated:

Phosphotase HMG-CoA reductase ka ho e fetola hore e be naha e sebetsang ea dephosphorylated. Liphetho tsa karabelo tsena ke ho thehwa ha sebopeho se sebetsang sa dephosphorylated e sebetsang ea HMG-CoA.

Ka lebaka leo, nakong ea ho monya, cholesterol ea eketseha. Nakong ena, ho fumaneha ha substrate ea mantlha bakeng sa motsoako oa k'holeseterole - acetyl - CoA ea eketseha (ka lebaka la ho ja lijo tse nang le lik'habohaedreite le mafura, kaha CoA acetyl e thehoa nakong ea ho phatloha ha glucose le mafura acid).

Sebakeng sa postabsorbent, glucagon ka proteiningenase A e tsosa phosphorylation ea HMG - CoA - reductase, e e fetohe boemong bo sa sebetseng. Ketso ena e matlafatsoa ke taba ea hore ka nako e tsoanang glucagon e phahamisa phosphorylation le inactivation ea phosphotase ea HMG-CoA reductase, ka hona e boloka phokotso ea HMG-CoA maemong a sa sebetseng a phosphorylated. Ka lebaka leo, motsoako oa k'holeseterole nakong ea postabsorption le nakong ea ho itima lijo e thibetsoe ke synto native synthesis. Haeba litaba tsa k'holeseterole lijong li tlisitsoe ho 2%, karolelano ea cholesterol ea endo native e fokotsehile haholo. Empa ho felisoa ka botlalo ha motsoako oa cholesterol ha ho etsahale.

Tekanyo ea thibelo ea cholesterol biosynthesis tlasa tšusumetso ea k'holeseterole e tsoang lijong e fapana ho ea ka batho. Sena se supa boits'oaro ba lits'ebetso tsa ho theha k'holeseterole. Ka ho fokotsa botebo ba motsoako oa cholesterol, ho ka khonahala ho fokotsa khatello ea mali maling.

Haeba ho leka-lekana pakeng tsa ho kenella k'holeseterole ka lijo le motsoako oa 'mele ka lehlakoreng le leng le phello ea bile acid le cholesterol ka lehlakoreng le leng e robehile, khatello ea cholesterol liseleng le liphetoho tsa mali. Litlamorao tse mpe ka ho fetisisa li amahanngoa le keketseho ea khatello ea cholesterol ea mali (hypercholesterolemia), ha menyetla ea ho holisa atherosulinosis le cholelithiasis e eketseha.

Familiaal hypercholesterolemia (HCS) - Foromo ena e atile haholo - e ka ba mokuli a le mong ho batho ba 200. Bofokoli bo futsitsoeng ho HCS ke tlolo ea ho amoheloa ha LDL ka lisele, ka hona, ho fokotseha hoa tekanyo ea catabolism ea LDL. Ka lebaka leo, khatello ea LDL maling e ea nyoloha, le cholesterol kaha ho na le bongata ba eona LDL. Ka hona, ka HCS, ho hlahisoa ha cholesterol ho li-tishu, haholo-holo letlalong (xanthomas), maboteng a methapo ea methapo ke tšobotsi.

Thibelo ea motsoako oa HMG-CoA reductase

Sehlahisoa sa ho qetela sa tsela ea cholesterol metabolic. E fokotsa sekhahla sa phetisetso ea mofuta oa HMG-CoA reductase, ka hona e thibela tlhahiso ea eona. Sebete se kopanya li-acid acid ka mafolofolo, ka hona, li-acid acid li thibela mosebetsi oa gene ea HMG-CoA. Kaha HMG-CoA reductase e teng kamora ho kopana ha batho ba ka bang 3, thibelo ea motsoako oa enzyme ena ea cholesterol ke molao o sebetsang.