Kaha ntho ena ke ea sehlopha sa li-alcohols, lebitso "cholesterol" ke lona feela le sebetsang, athe lebitso "cholesterol" (ka kotloloho "bile" ka lebaka la ho ikhetholla ha lona ho tloha gallstones) le ile la abeloa setsing ka moetlo - pele le fumaneha ka 1769 ke moemisi oa Lefora Pouletier de La Sal, e bonts'itse thepa ea mafura e hlakileng, eo ho eona e neng e kengoe qalong.
Ka lebaka la liphoso tse ling tsa letsoalo tsa bo-rasaense, cholesterol e phatlalalitsoe e le "sera No. 1" bakeng sa bophelo bo botle ba 'mele ka lilemo tse ngata, e ileng ea baka phetoho ea' nete indastering ea lijo, pharmacology le mekhoa ea kalafo - hammoho le lihlahisoa tse nang le mafura a tlase, lithethefatsi tse ncha le mekhoa e ileng ea fokotsa lefats'e haholo. metsoako maling, le sena sohle - le lisebelisoa tsa taolo ea "disenyi" e le hore e ka lula e behiloe leihlo.
Kaha mokhoa o motle oa ho hlahloba tšenyo ea ntlha e le 'ngoe kapa mokhoa o mong ke mokhoa oa ho e tlosa ho potoloha, sena se entsoe - ka lebaka leo, lefats'e lohle joale le kotula litholoana tse bosula tsa "lijo tse fokotsang", mme bo-ramahlale ba qobelloa ho etsa mabaka le ho ts'episa ho e lokisa. Empa sena se ka etsoa feela ka ho utloisisa tšimoloho le karolo ea 'nete ea ntho ea' mele.
Mesebetsi ea sehlooho ea cholesterol
Ntle le taba ea hore ke karolo ea bohlokoahali (fluidity stabilizer) ea membrane ea cytoplasmic, ho netefatsa ho tiea ha karolo ea eona e habeli ka lebaka la ho beoa ho kopaneng ha limolek'hule tsa phospholipid, cholesterol e iponahatsa e le sesosa sa taolo ea marang-rang a lisele tsa cell, ho thibela mali hemolysis. .
E boetse e sebetsa e le ntho ea ho qala bakeng sa tlhahiso ea metsoako ea sehlopha sa steroid:
- lihormone tsa corticosteroid;
- lihormone tsa thobalano;
- bile asiti;
- Li-vithamine tsa sehlopha sa D (ergocalciferorol le cholecalciferol).
Ha ho fanoa ka bohlokoa ba 'mele oa e mong le e mong oa sehlopha sena sa lintho, ho hlaka kotsi ea khaello ea lijo tse senang cholesterol kapa ho fokotseha hoa sekhahla sa ntho ena maling.
Ka lebaka la ho se sebetse ha eona ka metsing, ntho ena e ka tsamaisoa ke mali feela hammoho le liprotheine tsa transporter (apolipoprotein), ha li kopantsoe le lipoprotein complexes tse entsoeng.
Ka lebaka la ho ba teng ha li-apolipoprotein tse fapaneng (ka phapang ea boima ba limolek'hule, tekanyo ea tsona ea tropism bakeng sa cholesterol, hape le ka lebaka la bokhoni ba ho rarahana ho qhibiliha maling, le likarolo tse sa fetoheng tsa kristale ea cholesterol ho theha li-atherosranceotic plaque), mekhahlelo e latelang ea lipoprotein e khethollotsoe:
- letsoalo le phahameng (HDL, kapa boima bo phahameng ba limolek'hule, kapa HDL-lipoprotein);
- letsoalo le tlase (LDL, kapa boima ba limolek'hule tse tlase, kapa LDL-lipoprotein);
- letsoalo le tlase haholo (VLDL, boima bo tlase haholo ba limolek'hule, kapa sehlopha sa VPLL sa lipoprotein);
- chylomicrons.
Ho lisele tsa bokhabane, k'holeseterole e kenella e tlameletsoe ho li-chylomicrons, LDL kapa VLDL, ho ea sebete (ka ho tlosoa kamora 'mele) - ka ho tsamaisa li-apolipoproteins tsa sehlopha sa HDL.
Litšobotsi tsa Synthesis
E le hore li-plaque tse ling tsa atherosselotic li thehe k'holeseterole (eo ka nako e tšoanang e bang "lithapo" leboteng le senyehileng la "methapo") sebakeng seo kantle ho bona khafetsa ea mesifa e ka lebisang ponong ea lona - sebaka sa marang-rang, kapa li-hormone, kapa lihlahisoa tse ling, e lokela ho etsoa pele 'meleng ho e' ngoe ea libaka tse tharo:
- letlalo
- mala;
- sebete.
Kaha lisele tsa sebete (li-cytosol tsa bona le "endiclasmic reticulum") ke tsona phepelo ea mantlha ea karoloana (ka 50% kapa ho feta), motsoako oa ntho o lokela ho nkuoa ka nepo ho tloha ponong ea karabelo e etsahalang ho eona.
Mokhoa oa k'holeseterole o hlaha ka mekhahlelo e 5 - ka sebopeho se latellanang:
- meallonate;
- isopentenyl pyrophosphate;
- squalene;
- lanosterol;
- ha e le hantle k'holeseterole.
Liphetoho tse ngata li ne li ke ke tsa khonahala ntle le ho nka karolo ha li-enzyme tse ithutetsang karolo ka 'ngoe ea mohato ona.
Video ka tlhahiso ea cholesterol:
Lirosa tse amehang ho hlahiseng taba
Mokhahlelong oa pele (o kenyelletsa ts'ebetso e meraro), ho thehoa ha acetoacetyl-CoA (mona CoA - coenzyme A) e qaliloe ke acetyl-CoA-acetyltrasferase (thiolase) ka fusion ea limolek'hule tse 2 tsa acetyl-CoA. Ho ekelletsa moo, ka ho nka karolo ha HMG-CoA synthase (hydroxymethyl-glutaryl-CoA synthase), synthece ho tloha acetoacetyl-CoA le molek'hule e ngoe ea acetyl-CoA ꞵ-hydroxy-ꞵ-methylglutaryl-CoA ea khonahala.
Kamor'a phokotso ea HMG (ꞵ-hydroxy-ꞵ-methyl-glutaryl-CoA) ka ho qaqisa sekhechana sa HS-CoA ka ho nka karolo ha NPP-hydroxymethyl-glutaryl-CoA reductase (HMG-CoA reductase), sehlahisoa sa pele sa mantlha, k'holeseterole ea pele. )
Boemong ba syntopine ea isopentinyl pyrophosphate, ts'ebetso tse 'ne li etsoa. Ka mevalonate kinase (ebe phosphomevalonate kinase), Mevalonate e fetoloa hore e be 5-phosphomevalonate ho 1 le 2 Mevalonate kinase (ebe phosphomevalonate kinase), ebe ho isa ho 5-pyrophosphomevalonate, e fetoha 3-phospho-5-pyrophosphomephostionate ea 3 phphophosphomephostionate 3. (ka ho nka karolo ha enase ea kinase).
Ts'ebetso ea ho qetela ke decarboxylation le dephosphorylation ka sebopeho sa isopentinyl pyrophosphate (e qaliloe ke ho nka karolo ha enzyme pyrophosphomevalonate decarboxylase).
Khethisong ea squalene, isomerization ea pele ea isopentenyl pyrophosphate ho dimethylallyl pyrophosphate e etsahala (tlasa ts'usumetso ea isopentyl phosphatisomerase), ebe isopentenyl pyrophosphate condence ka dimethylallyl pyrophosphate (tlamo ea elektroniki e thehiloe pakeng tsa C.5 ea pele le C5 ntho ea bobeli) ka sebopeho sa geranyl pyrophosphate (le cleavage ea molek'hule oa pyrophosphate).
Boemong bo latelang, tlamahano pakeng tsa C5 isopentenyl pyrophosphate le C10 geranyl pyrophosphate - ka lebaka la ho ferekana ha ea pele le ea bobeli, farnesyl pyrophosphate e thehoa mme molek'hule o latelang oa pyrophosphate o tlosoa ho C15.
Mokhahlelong ona o phethela ka ho phahama ha limolek'hule tse peli tsa farnesyl pyrophosphate sebakeng sa C15- C15 (hlooho-to-hlooho) ka ho tlosoa ha limolek'hule tse peli tsa "pyrophosphate" hang. Bakeng sa phumano ea limolek'hule ka bobeli, ho sebelisoa likarolo tsa lihlopha tsa pyrophosphate, e 'ngoe ea tsona e hlakotsoe hang-hang, e lebisang ho bopeng prequale pyrophosphate. Ha NADPH e fokotseha (ka ho tlosoa ha pyrophosphate ea bobeli), ntho ena e mahareng (e tlas'a tšusumetso ea squalene synthase) e fetoha skavalen.
Khethong ea lanosterol ho na le ts'ebetso ea 2: ea pele e fela ka sebopeho sa squalene epoxide (tlas'a tšusumetso ea squalene epoxidase) ea bobeli - ka cyclization ea squalene epoxide ho sehlahisoa sa ho qetela sa sethala - lanosterol. Ho tlosa sehlopha sa methyl ho tloha C14 ho C13, le ho tloha C8 ho C14 o tseba oxidosqualene-lanosterol cyclase.
Mokhahlelo oa hoqetela o kenyelletsa tatellano ea lits'ebetso tse 5. Ka lebaka la oxidation ea C14 Sehlopha sa methyl sa lanosterol se hlahisa motsoako o bitsoang 14-desmethylanosterol. Kamora ho tlosoa ha lihlopha tse ling tse peli tsa methyl (ho C4) ntho e fetoha zymosterol, 'me ka lebaka la phallo ea tlamo ea bobeli C8= C9 ho beha C8= C7 sebopeho sa δ-7,24-cholestadienol se etsahala (tlasa ketso ea isomerase).
Kamora ho tsamaea ka bobeli bond C7= C8 ho beha C5= C6 (ka sebopeho sa desmosterol) le ho khutlisetsoa ha setlamo se habeli mokokotlong oa lehlakoreng, ntho ea ho qetela e thehiloe - k'holeseterole (kapa ho fapana le moo, k'holeseterole). Enzyme ea "δ" 24-reductase e "tsamaisa" mohato oa hoqetela oa kolesterol.
Ke eng e amang mofuta oa cholesterol?
Ka lebaka la solubility e tlase ea lipoprotein tse tlase tsa boima ba molek'hule (LDL), tloaelo ea bona ea ho chesa likristale tsa cholesterol (ka sebopeho sa litheolelo tsa methapo ea methapo methapong e eketsang menyetla ea mathata a pelo le methapo), lipoprotein tsa sehlopha sena hangata li bitsoa "cholesterol e mpe", ha lipoprotein tse phahameng tse nang le lipoprotein tse phahameng tse nang boima ba molek'hule (HDL) e nang le thepa e fapaneng (ntle le kotsi ea atherogenicity) e bitsoa k'holeseterole "e na le thuso."
Ho latela kamano ea Tlhahiso ena (mmele o ke ke oa thusa ka letho kapa ka mokhoa o seng kotsi), leha ho le joalo, hona joale ho ntse ho rehelloa mehato bakeng sa batho ba nang le tekanyo e phahameng ea methapo ea methapo ea methapo ho laola le ho fokotsa LDL maemong a nepahetseng.
Ka palo e fetang 4,138 mmol / l, khetho ea lijo e khothalletsoa ho fokotsa maemo a tsona ho 3.362 (kapa ka tlase ho moo), boemo bo kaholimo ho 4.914 e sebetsa e le sesupo sa ho fana ka kalafo ho fokotseha ts'ebeliso ea lithethefatsi ka mokhoa o sa tloaelehang.
Keketseho ea karoloana ea mali ea "cholesterol e mpe" e bakoa ke lintlha:
- ho ikoetlisa ka tlase (ho se sebetse hantle 'meleng);
- ho nona haholo (ho itšetleha ka lijo), hammoho le litlamorao - boima bo feteletseng kapa botenya;
- ho se leka-lekane ha ho ja - ka bongata ba mafura a fetisitsoeng, li-carbohydrate tse bonolo, (li-sweets, li-muffin) ho senyeha ha litaba tsa pectin, fiber, livithamini, likarolo tsa tšireletso, mafura a acid ea polyunsaturated composition;
- boteng ba tahi e tloahelehileng ea lelapa (ho tsuba, ho nwa joala ka mokhoa oa lino tse fapaneng, tlhekefetso ea lithethefatsi).
Ho ba teng ha psychatic e sa foleng ea mantlha ho na le matla a tšoanang:
- lefu la gallstone;
- mathata a endocrine ka hyperproduction ea lihormone tsa adrenal cortex, khaello ea li-hormone tsa qoqotho kapa tsa thobalano, kapa lefu la tsoekere;
- renal le hepatic ho haella ka mathata a methati e itseng ea lipoprotein tse "bohlokoa" tse etsahalang litho tsena;
- lefutso le lefu la ho fufulela.
Boemo ba metabolism ea cholesterol bo latela ka kotloloho ho boemo ba microflora ea mala, e khothalletsang (kapa e thibelang) ho fufuleloa ha mafura a amanang le phepo, hape e nka karolo ho kopantseng, phetolelong, kapa tshenyetsong ea li-sterols tsa tlhaho ea kantle le ea endo native.
Mme ka lehlakoreng le leng, ho fokotsa sesupo sa "lead" cholesterol lead:
- thuto ea 'mele, lipapali, motjeko;
- ho boloka bophelo bo botle ntle le ho tsuba le joala;
- Lijo tse nepahetseng ntle le ho ja lijo tse nang le phepo e ngata tse nang le phepo e ntle, tse nang le mafura a mangata a phoofolo e nang le sebopeho se felletseng - empa se na le dikahare tse lekaneng tsa furu, li-acids tsa polyunsaturated tse mafura, lintlha tsa lipotropic (lecithin, methionine, choline), likarolo tsa trace, livithamini.
Video e tsoang ho setsebi:
Ts'ebetso e joang 'meleng?
Ke karolo ea 20% feela ea cholesterol e kenang 'meleng ka lijo tseo o li jang - e hlahisa 80% e setseng ka boeona, ho ekelletsa ho sebete, ts'ebetso ea motsoako e etsoa ke reticulum e boreleli ea lisele:
- mala;
- litšoelesa tsa adrenal;
- seso
- litsoelesa tsa botšehali.
Ntle le mochine oa khale oa ho hlahisa molek'hule ea cholesterol e hlalositsoeng ka holimo, ho a khoneha ho e haha o sebelisa mokhoa o seng oa meroalo. Kahoo, e 'ngoe ea likhetho ke ho theha ntho ho tsoa ho glucose (e hlahang ka li-enzyme tse ling le tlasa maemo a mang a setho.
