Iwu nke cholesterol njikọ

Usoro mmeghachi omume cholesterol

2. Nkoputa nke isopentenyl diphosphate. Na ọkwa a, a na-etinye ahihia fosphate atọ na mevalonic acid, mgbe ahụ ọ ga-decarboxylated ma dehydrogenated.

3. Mgbe agwakọchara mkpụrụ ndụ atọ nke isopentenyl diphosphate, a na-ekekọta farnesyl diphosphate.

4. Ngwakọta nke squalene na-apụta mgbe ejiri agbụ farnesyl diphosphate abụọ.

5. Mgbe mmeghachi omume dị mgbagwoju anya, ahịrị squalene cyclizes na-aga lanosterol.

6. Mwepụ nke ìgwè methyl ngafe, mweghachi na isomerization nke molecule na-eduga n'ọdịdị cholesterol.

Iwu nke ọrụ hydroxymethylglutaryl-S-CoA reductase

3. Ọnụego chosyerol biosynthesis na-adabere na ịta protein a na-ebu akọwana-enye maka njikọta na mbufe nke hydrophobic intermediate synthesis metabolites.

Can nwere ike jụọ ma ọ bụ hapụ echiche gị.

Isi ihe na-achịkwa bụ mmeghachi omume nke ịmepụta mevalonic acid.

1. Allosteric iwu. Cholesterol, yana imeju - na bile acids na - egbochi HMG-CoA reductase.

2. Ntughari njikọta nke HMG-CoA reductase cholesterol.

3. Iwu site na phosphorylation-dephosphorylation nke HMG-CoA reductase, ụdị nke na-abụghị phosphorylated. Glucagon na-akpata mmebi, insulin na-ebutekwa ngagharị site na usoro mmeghachi omume dị mgbagwoju anya. Ya mere, onodu cholesterol na-agbanwe agbanwe na mgbanwe mgbanwe na steeti absorbent na postabsorption.

4. Ọnụego mkpesa nke HMG-CoA reductase na imeju a na-enwe mgbanwe doro anya: ọ kachasị n’etiti abalị, na nke kachasi ụtụtụ.

Mgbanwe cholesterol ester

N'ime mkpụrụ ndụ ọgbụgba cholesterol na - apụta mgbe ekpughere ya acyl-CoA-cholesterol-acyltransferase (AHAT):

Acyl-CoA + Cholesterol ® NS-CoA + Acylcholesterol

N'ime mkpụrụ ndụ, akpụrụ akpụ linoleylcholesterol. A na - ahụta Esteri na cytosol dịka akụkụ nke ụmụ irighiri mmiri. Nmekorita esters, n’otu aka, dika ihe eji ewepu cholesterol kari n’onu, ma n’aka nke ozo, dika ihe eji echekwa cholesterol n’ime sel. Nchikota a na - enweta nzoputa a site na ntinye aka nke enzymes esterasehydrolyzing cholesterol esters:

Acylcholesterol + H₂O ® Fatty Acid + cholesterol

Ngwakọta na hydrolysis nke esters na-arụ ọrụ nke ọma na sel nke adrenal cortex.

Na lipoproteins ọbara ester guzobere na ntinye nke lecithin-cholesterol-acyltransferase (LHAT), na-ahụ maka mbufe nke acyl site na lecithin gaa cholesterol. LHAT guzobere imeju, na-abanye ya n'ọbara ma kegide na lipoproteins. LHAT kachasị arụ ọrụ na HDL, ebe edebere ya na elu igwe. Cholesterol esters guzobere ebe a bụ hydrophobic ma mikpuru n'ime mkpo isi. N'ime monolayer phospholipid, enwere ohere maka cholesterol, nke enwere ike jupụta cholesterol site na membranes cell ma ọ bụ na lipoproteins ndị ọzọ. Ya mere, HDL yiri ka ọ bụ ọnyà cholesterol n'ihi ihe LHAT mere.

Ọkpụkpụ Bile Acid

N'ime imeju, a gbanwere akụkụ nke kọlestrọl ka ọ bụrụ acid. Enwere ike ịtụle Bile acids dị ka usoro nke cholanic acid. A choputaghi cholanic acid n’anu ahu. Na hepatocytes sitere na cholesterol, a na --ebe acid isi bu - chenodeoxycholic na cholic. Mgbe secretion nke bile n'ime eriri afọ n'okpuru ọrụ nke enzymes nke akụkụ eriri afọ, a na --ebe acid bile ha - lithocholic na deoxycholic. A na-amịkọrọ ha na eriri afọ, ya na ọbara nke akwara portal na-abanyekwa imeju, ma banye na bile. Bile nwere ihe ndi ozo bu conjugated bile acid, dika. Bu, glycine ma obu taurine ha nwere. Nwe ntụpọ nke bile acid dị na bile bụ ihe dịka 1%.

Akụkụ bụ isi acid bile na-etinye aka na ya hepatoenteric mgbasa.Obere akụkụ nke acid bile - ihe dị ka 0,5 g kwa ụbọchị - na-apụ apụ na feces. Nke a kwụrụ ụgwọ site na njikọta nke bile acid ọhụrụ n'ime imeju, a na-emelite ego nke bile acid n'ihe dị ka ụbọchị iri.

Cholesterol na - apụtakarị site na eriri afọ. Ọ na-abanye eriri afọ nri na site na imeju dị ka akụkụ nke bile. Cholesterol abanye n'ime ọbara nwere ihe pere mpe nke sitere na bile (cholesterol endogenousmejupụtara imeju) na irighiri ihe sitere na nri (cholesterol na-efe efe) Wepu cholesterol site na akwara sitere na nsị ya iji mee ka ọ nwee acid na imeju, ihe na-esochi ya bụ feces (ihe dịka 0,5 g kwa ụbọchị) yana site na chorelerol a na - agbanweghi agbanwe (yana ọrịa feces).

Na Ọnọdụ steeti:

(Cholesterol)_njedebe + Cholesterol_bu) - (Cholesterol)_ikwu + Bile acids_ikwu) = 0

Ọ bụrụ n ’nguzozi a gha agbagha, uche nke cholesterol n’arụ na ọbara na-agbanwe. Mmụba ọbara cholesterol - hypercholesterolemia. Nke a na - eme ka ohere nke atherosclerosis na ọrịa gallstone dịkwuo elu.

AKWGKWỌ LIPID EGO

Ọ na - ahazi sistem Lipid. Ogologo oge echiche mmetụta uche na-adịghị mma, mmụba na mwepụta nke catecholamines banye n'ọbara nwere ike ibute oke ibu. Ihe omume glucagon Na usoro akwara mmiri dị n'ụdị catecholamines.

Adrenaline na norepinephrine mụbaa ọrụ nke lipase anụ ahụ na ọnụego nke lipolysis na adipose anụ ahụ, n'ihi nke a, ọdịnaya nke asịd na plasma ọbara na-abawanye.

Insulin nwere mmetụta dị iche nke adrenaline na glucagon na lipolysis na nchịkọta nke ọdụdụ abụba.

Uto homonụ na-akpali lipolysis, webata njikọ nke acenylate cyclase. Hypofunction hypofunction na-eduga n'inweta abụba anụ ahụ (oke ibu oke ibu).

Thyroxine, homonụ mmekọahụna-emetụtakwa metabolism lipid. Mwepu nke glands nwoke na anumanu na - eme ka inye oke ibu ghara ibu ibu.

LIPID METABOLIC DISORDERS

Cholesterol bụ steroid akọwapụtara maka anụmanụ anụmanụ. Isi ebe etolite ya n’ahụ mmadụ bụ imeju, ebe a na-arụ ọrụ cholesterol nke 50%, a na-akpụkọta 15-20% n’ime obere eriri afọ, a na-akpụkọta akụkụ ahụ ndị ọzọ n’akpụkpọ anụ ahụ, eriri ahịhịa adrenal na gonads. Egosiputa uzo esi guzo cholesterol na uzo o si emefu ya na fig 22.1.

Fig. 22.1. Guzobe na nkesa nke cholesterol n’arụ.

A ga-ekezi cholesterol nke ahụ mmadụ (ọnụọgụ ruru ihe ruru 140 g) na ọnọdụ dịka ọdọ mmiri atọ.

30 g), na-agbanwe ngwa ngwa, mejupụtara cholesterol nke mgbidi eriri afọ, plasma ọbara, imeju na akụkụ ndị ọzọ parenchymal, mmeghari ohuru na - apụta na ụbọchị 30 (1 g / ụbọchị),

50 g), jiri nwayọ were cholesterol nke aru na akwara ndị ọzọ,

60 g), cholesterol dị nwayọ gbanwere akwara azụ na ụbụrụ, anụ ahụ na - ejikọta ọnụ, mmelite mmelite ka ana-agbakọ n'ime afọ.

Ngwakọta nke cholesterol na-apụta na cytosol sel. Nke a bụ otu n'ime ụzọ metabolic kachasị ogologo na ahụ mmadụ. Ọ na-aga n’ihu nke atọ: nke mbụ mechiri mevalonic acid, nke abụọ nwere nguzo nke squalene (larịị hydrocarbon mejupụtara atọm carbon). N’agba nke atọ, squalene na-agbanwe ka ọ bụrụ irighiri ihe lanosterol, mgbe ahụ enwere mmeghachi ugboro 20 na-agbanwe nke na-eme ka lanosterol na cholesterol.

N'ime ụfọdụ anụ ahụ, kọlekọ hydroxyl cholesterol na - ewepụta etolite esters. A na-ejikwa mmeghachi ahụ enzyme AHAT intracellular AHAT (acylCoA: cholesterol acyltransferase). Mmeghachi mmekpa ahụ pụtara na ọbara na HDL, ebe enzyme LHAT (lecithin: cholesterol acyltransferase) dị. Cholesterol esters bu nke eji ebu obara jee ya ma obu tinye ya n ’ulo nga. N'ime ọbara, ihe dịka 75% nke cholesterol dị n'ụdị esters.

A na-achịkwa njikọta cholesterol site na-emetụta ọrụ na ego nke enzyme igodo nke usoro - 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase).

A na-enweta nke a n'ụzọ abụọ:

1. Phosphorylation / dephosphorylation nke HMG-CoA reductase. Insulin na-akpali dephosphorylation nke HMG-CoA reductase, si otú a tụgharịa ya na steeti nọ n'ọrụ. Yabụ, na oge oriri, njikọta cholesterol na-abawanye. N'ime oge a, nnweta nke mkpụrụ amalite maka njikọta, acetyl-CoA, na-abawanye. Glucagon nwere mmetụta nke na-emegide ya: site na protein kinase A, ọ na - akpali phosphorylation nke HMG-CoA reductase, na - atụgharị ya n'ọnọdụ adịghị arụ ọrụ. N'ihi ya, a na-egbochi njikọta cholesterol n'oge postabsorption na n'oge ibu ọnụ.

2. Ihe mgbochi nke njikọta HMG-CoA reductase.Cholesterol (ngwaahịa njedebe nke ụzọ metabolic) na-ebelata ọnụego ntụgharị nke mkpụrụ ndụ HMG-CoA reductase, si otú a na-egbochi njikọ nke ya, na bile acid na-ebutekwa otu mmetụta.

A na-ebugharị cholesterol ọbara dị ka akụkụ nke ọgwụ ahụ. LP na-enye cholesterol mmiri n’arụ, na-ekpebi usoro ọ ga-esi n’etiti akụkụ ahụ na mwepụ nke ahụ. A na-enye cholesterol na - emeju imeju dịka akụkụ nke ChM. N'ebe ahụ, ya na cholesterol na-arụ ọrụ ọnụ, ọ na-etolite ego anyị na-enweta. Na hepatocytes, a na-etinye mkpọsa na cholesterol na VLDL, n'ụdị a na-ezobe n'ime ọbara. N'ime ọbara, VLDL n'okpuru ọrụ nke LP-lipase, nke hydrolyze TAG ka glycerol na ọdụdụ abụba, gbanwere na LSPP, emesia na LDL nwere ihe choro cholesterol ruru 55% na esters ya. LDL bu uzo eji ebu cholesterol nke eji enye ya aru (70% nke cholesterol na ndi esters n’ime obara bu akuku LDL). LDL sitere na ọbara na-abanye na imeju (ihe ruru 75%) yana anụ ahụ ndị ọzọ nwere ndị na-anabata LDL n’elu elu ha.

Ọ bụrụ na ụba cholesterol na-abanye na sel karịrị mkpa ya, mgbe ahụ, a na-egbochi mkpụkọ nke ndị na - anabata LDL, nke a na --eme ka mmiri cholesterol na ọbara. Site na mbelata nke ịlele cholesterol dị na sel, na nnabata, a na-arụ ọrụ nchịkọta receptor. Hormones na-etinye aka na nhazi nke njikọta mkpokọ LDL: insulin, triiodothyronine na homonụ mmekọahụ na-abawanye na nguzobe nke ndị na - anabata ya, glucocorticoids na - ebelata.

N’agha a na-akpọ “cholesterol Return transport”, i.e. okporo ụzọ nke na-ahụ na nlọghachi nke cholesterol n’arụ, HDL na-arụ ọrụ bụ isi. A na-achịkọta ha n'ime imeju n'ụdị nhazi nke ọmụmụ akabeghị onwe nwere ihe cholesterol na TAG. Ihe ntụgharị nke HDL n'ọbara juputara na cholesterol, na-anata ya site na LP na mkpụkọ sel ndị ọzọ. Thebufe cholesterol na HDL gụnyere enzyme LHAT nke dị n’elu ala ha. Enzyme a na - ejikọ nsị acid acid sitere na phosphatidylcholine (lecithin) ruo cholesterol. N'ihi nke a, a na-emepụta motọ hydrophobic nke cholesterol ester, nke na-akpali n'ime HDL. N'ihi ya, ị notụbiga mmanya HDL, nke cholesterol, jupụta na HDL 3 - ụmụ irighiri ihe dị ukwuu ma bukwanu ibu. HDL 3 mgbanwe cholesterol esters maka TAG dị na VLDL na STD na ntinye nke protein a kapịrị ọnụ nke na-ebufe cholesterol esters n'etiti lipoproteins. N'okwu a, HDL 3 tụgharịa bụrụ HDL2, nha ya na-abawanye n'ihi ụba TAG. VLDL na STDL n'okpuru LP-lipase ka agbanwere ka ọ bụrụ LDL, bụ nke na-ebubata cholesterol na imeju. A na-ekenye obere akụkụ cholesterol na imeju nke HDL2 na HDL.

Synthesis nke bile acid. Na imeju, 500-700 mg nke bile acids kwa ụbọchị bụ kọlọtọ site na cholesterol. Nhazi ha tinyere mmeghachi omume nke ntinye nke otu hydroxyl na ntinye nke hydroxylases na mmeghachi nke oxidation nke akuku nke cholesterol (Fig 22.2):

Fig. 22.2. Usoro nke nguzogide nke bile acid.

Mmeghachi omume mbụ - nhazi nke 7-a-hydroxycholesterol - bụ nhazi. A na-egbochi ọrụ nke enzyme nke na-ejigide mmeghachi omume a site na njedebe ngwaahịa nke ụzọ, bile acid. Usoro usoro ọzọ bụ phosphorylation / dephosphorylation nke enzyme (ụdị phosphorylated nke 7-a-hydroxylase na-arụ ọrụ). Iwu ga - ekwekwa omume site na ịgbanwe ego nke enzyme: cholesterol na - akpata mmịnye nke mkpụrụ nke 7 a-hydroxylase, na mmeghachi nke bile acid. Homonụ thyroid na-ebute njikọ nke 7-a-hydroxylase, na estrogen repress. Mmetụta dị otú ahụ nke estrogen na njikọ nke bile acids na-akọwa ihe kpatara ọrịa ọrịa gallstone ji emetụta ụmụ nwanyị ugboro atọ 3-4 karịa karịa na ụmụ nwoke.

A na-akpọ Cholic na chenodeoxycholic acid ndị a gbanyere na cholesterol “Primari bile acid”. Otutu acid a na - emeghari onyonyo - mgbakwunye nke glycine ma obu taurine ndi mo na acid nke bile acid. Conjugation na-ebido site n'ụdị nke bile acid - usoro nke CoA, wee jikọta taurine ma ọ bụ glycine, n'ihi nke a, e guzobere 4 iche iche nke conjugates: taurocholic na taurohenodeoxycholic, glycocholic na glycohenodeoxycholic acid. Ha bụ emulsifiers siri ike karịa acid ndị mbụ. A na-eme conjugates nwere glycine ugboro atọ karịa na taurine, ebe ọ bụ na oke nke taurine dị n'ahụ nwere oke. Na eriri afọ, ntakịrị ihe conjugates nke acid bile na-arụ ọrụ n'okpuru enzymes nje na-agbanwe n'ime acid nke abụọ. Deoxycholic acid, nke emere site na cholic, na lithocholic, nke emere site na deoxycholic, anaghị enwe mmiri nke ukwuu ma na-agbadata nwayọ karịa eriri afọ.

Ihe dị ka 95% nke bile acid ndị na-abanye na eriri afọ na-alaghachi umeji site na akwara Portal, mgbe ahụ, a na-ezobe ha ọzọ n'ime bile ma jiri ha mee ihe nke abụba. A na-akpọ okporo ụzọ mmiri a na-akpọ bile acid. Site na oria, a na - ewepu ihe ndi ozo bile acid.

Ọrịa gallstone (cholelithiasis) bụ usoro ihe omimi nke okwute na - ebute n’ime gallbladder, ihe ndabere bụ cholesterol.

Mwepu nke cholesterol n’ime bile kwesiri ijikọ ya na ọgwụ bile acid na phospholipids ndị na-eme ka hydrophobic cholesterol ụmụ irighiri mmiri dị na steeti micellar. Ihe mere kpatara mgbanwe ji jupụta na bile acid na cholesterol na bile bụ: nri bara ụba kọlestrọl, nri-kalori nke ukwuu, mgbagide agbụrụ dị na gallbladder, ụkọ enterohepatic, na -akpọ nsị nke acid bile, ọrịa otolite.

N'ime ọtụtụ ndị ọrịa nwere cholelithiasis, njikọta cholesterol na-abawanye, yana njikọta nke bile acids na ya na-ebelata, nke na-eduga na mgbasa nke ọnya cholesterol na bile acid zoro ezo na bile. N’ihi ya, cholesterol na-amalite iku ume n’otuto ahụ, na-akpụ ụdara viscous nke ji nwayọ nwayọ. Mgbe ụfọdụ, etinyere ya na bilirubin, protein na nnu nke calcium. Nkume nwere ike inwe naanị cholesterol (okwute cholesterol) ma ọ bụ ngwakọta nke cholesterol, bilirubin, protein na calcium. Nkume cholesterol na-achakarị ọcha, okwute ndị juputara na-acha aja aja na ndo dị iche iche.

N'ime mmalite nke ịmebe okwute, enwere ike iji chenodeoxycholic acid dịka ọgwụ. Ozugbo n'ime gallbladder, ọ na-eji nwayọọ nwayọọ gbazee okwute cholesterol, mana nke a bụ usoro nwayọ nke na-adị ọtụtụ ọnwa.

Atherosclerosis bụ ọrịa akwara nke gosipụtara mbadamba nkume atherogenic n’elu ime nke mgbidi vaskụla. Otu n'ime isi ihe kpatara mmepe nke ụdị ọrịa a bụ imebi nguzozi n'etiti oriri cholesterol site na nri, njikọ ya na mwepụ ahụ ya. Ndị ọrịa nwere atherosclerosis ejirila nchịkọta LDL na VLDL bulie elu. Enwere mmekọrịta na-adịghị mma n'etiti ịta ụta HDL yana ohere nke ịmalite ọrịa atherosclerosis. Nke a kwekọrọ n'echiche nke ịrụ ọrụ nke LDL dị ka ndị na-ebu cholesterol na anụ ahụ, na HDL site na anụ ahụ.

Ihe dị mkpa metabolic "ihe dị mkpa" maka mmepe nke atherosclerosis bụ hypercholesterolemia. (cholesterol dị elu n’ime ọbara).

Hypercholesterolemia malitere:

1. n'ihi ịba ụba cholesterol, carbohydrates na abụba,

2. Arịrị mkpụrụ ndụ ihe mejupụtara ya na ntụpọ sitere na ihe owuwu nke LDL ma ọ bụ nnabata apoB-100, yana ịbawanye ụba ma ọ bụ nzuzo nke apoB-100 (n'ihe gbasara ezinụlọ ịba ụba hyperlipidemia, nke mgbakwunye ọbara na cholesterol na TAG).

Ọrụ dị mkpa na usoro nke mmepe nke atherosclerosis bụ nke mgbanwe nke ọgwụ na-arụ. Mgbanwe na nhazi nke akpịrị na protein dị na LDL na-eme ka ha bụrụ ndị mba ọzọ n'anụ ahụ, yabụ ohere ọzọ maka ijide site na phagocytes.

Mgbanwe ọgwụ ọjọọ nwere ike ime site n'ọtụtụ usoro:

1. glycosylation nke protein na-eme mgbe ịta glucose n'ọbara na-abawanye,

2. mgbanwe peroxide, na-eduga na mgbanwe na lipids na lipoproteins yana nhazi nke apoB-100,

3. ịmepụta nke autoimmune complexes nke LP-antibody (ọgwụ ndị a gbanwere nwere ike ime ka echichi nke autoantibodies).

LDL gbanwetụrụ site na macrophages. Edebeghi usoro a site na cholesterol etinye, dịka n'ihe banyere ịbanye na mkpụrụ ndụ site na ndị na-anabata ya, ya mere macrophages juputara na cholesterol ma ghọọ 'sel ụfụfụ' na-abanye n'ime oghere subendothelial. Nke a na - eduga n’ịpụta oghere oghere ma ọ bụ iberibe mgbidi nke arịa ọbara. N'oge a, vaskụla endothelium nwere ike ijigide usoro ya. Site na mmụba nke ọnụ ọgụgụ ụfụfụ, mbibi endothelial na-apụta. Mbibi so na-eme ka platelet na-arụ ọrụ. N’ihi ya, ha na-ezochi thromboxane, nke na-akpali njikọta platelet, ma na - amalitekwa ihe na - ebute platelet, nke na - akpali mmụba nke mkpụrụ ndụ akwara dị mma. Nke ikpeazụ na-esi n'etiti ntụgharị na etiti gaa na etiti ime mgbidi mgbidi ahụ, si otú a na-enye aka na uto nke ihe ncheta. Ọzọkwa, ihe ncheta ahụ na-apụta site na anụ ahụ fibrous, mkpụrụ ndụ ndị dị n'okpuru akpụkpọ ahụ bụ necrotic, a na-etinyekwa cholesterol n'ime oghere dị n'ime. Na akụkụ ikpeazụ nke mmepe, a na-eji salts calcium na -eme ihe ncheta ahụ wee ghọọ oke. Na mpaghara ncheta, ọgbụgba ọbara na-etolitekarị, na-egbochi oghere nke arịa ahụ, nke na-eduga na nnukwu ọgbụgba ọbara n'akụkụ anụ ahụ kwekọrọ na mmepe nke nkụchi obi.

A na-eme usoro nhazi nke cholesterol - enzyme isi ya (HMG-CoA reductase) n'ụzọ dị iche iche.

Phosphorylation / dephosphorylation nke HMG mbelata. Site na mmụba na insulin / glucagon ruru, enzyme a na - eme phosphorylates ma gafere ọnọdụ arụ ọrụ. A na - eme insulin ahụ site na enzymes abụọ.

HMG-CoA reductase kinase phosphatase, nke na-atụgharị kinase ka ọ bụrụ ọnọdụ enweghị nkụda mmụọ:

Phosphotase HMG-CoA reductase site na-atụgharị ya ka ọ bụrụ steeti na-arụ ọrụ ike. Nsonaazụ nke mmeghachi omume ndị a bụ nguzobe nke ụdị dephosphorylated arụ ọrụ nke HMG-CoA reductase.

N'ihi ya, n'oge oge oriri, cholesterol na-abawanye. N'ime oge a, nnweta nke mkpụrụ mbụ maka njikọta cholesterol - acetyl - CoA na-abawanye (n'ihi iri nri nwere carbohydrates na abụba, ebe ọ bụ na etolite coA acetyl n'oge ọgbụgba nke glucose na abụba).

Na steeti postabsorbent, glucagon site na nchebe nchebe A na-akpali phosphorylation nke HMG - CoA - mbelata, na-eme ka ọ bụrụ ọnọdụ adịghị arụ ọrụ. A na - eme ka ihe a dịkwuo mma site n'eziokwu ahụ bụ na n'otu oge glucagon na - akpali phosphoase ma na - egbochi phosphotase nke HMG-CoA reductase, si otu a na - edebe HMG-CoA reductase na ọnọdụ nke anaghị arụ ọrụ. N'ihi nke a, a na - egbochi njikọta cholesterol n'oge postabsorption na n'oge ibu ọnụ site na njikọta endogenous. Ọ bụrụ na ewetara ọdịnaya cholesterol na nri n'ime 2%, yabụ njikọ nke cholesterol na-emebi emebi belatara nke ọma. Mana ịkwụsịsị cholesterol zuru ezu anaghị eme.

Ogo nke cholesterol biosynthesis n’okpuru mmetụta cholesterol na-esite n’ihe oriri dịgasị iche n’onwe mmadụ. Nke a na - egosi na usoro nke cholesterol guzobe. Site na ibelata ike cholesterol synthesis, ọ ga - ekwe omume belata itinye uche ya na ọbara.

Ọ bụrụ na ntụpọ dị n'etiti oriri nke cholesterol na nri na njikọ ya n'ime ahụ n'otu aka na mwepu nke bile acid na cholesterol n'akụkụ nke ọzọ, agbaji kọlesterol n'ime akwara na ọbara gbanwere. Ihe nsonaazụ kachasị njọ na-esonyere na mmụba nke ịba ụba nke cholesterol (hypercholesterolemia), ebe ohere nke etolite atherosclerosis na cholelithiasis na-abawanye.

Familial hypercholesterolemia (HCS) - ụdị a bụ ihe a na - ahụkarị - ihe dịka 1 onye ọrịa n’otu narị mmadụ abụọ. Mpempe e ketara eketa na HCS bụ mmebi nke nnabata nke LDL site na mkpụrụ ndụ, yabụ, mbelata mbelata LDL catabolism. N'ihi ya, itinye uche nke LDL n'ọbara na-ebili, yana kọlesterol ebe ọ bụ na enwere ọtụtụ n'ime LDL. Ya mere, na HCS, itinye cholesterol na akwara, na akpụkpọ ahụ (xanthomas), na mgbidi nke akwara bụ ihe e ji mara ya.

Mkpokọta njikọta nke HMG-CoA reductase

Ngwaahịa ikpeazụ nke usoro cholesterol metabolic way. Ọ na -ebelata ọnụego ntụgharị nke mkpụrụ ndụ HMG-CoA reductase, si otú a na-egbochi njikọ nke ya. Imeju na-eme ka mmiri ọgwụ na-arụ ọrụ na cholesterol site na cholesterol, yabụ bile acids na-egbochi ọrụ HMG-CoA reductase gene. Ebe ọ bụ na HMG-CoA reductase dị adị mgbe ọ jikọchara ihe dịka atọ, mgbochi nke njikọta enzyme a cholesterol bụ usoro dị irè.