Imikorere ya Platelet

Plateletes (trombocytes) ni uduce duto twa cytoplazme yarekuwe muri cytoplazme ya Megakaryocyte ikuze mumitsi.Nubwo Megakaryocyte ariwo mubare muto wa selile hematopoietic selile mu magufa, bingana na 0,05% gusa yumubare wuzuye wa selile nucleaux selile, platine bakora ningirakamaro cyane mumikorere ya hemostatike yumubiri.Buri Megakaryocyte irashobora gutanga platine 200-700.

Umubare wa platel yumuntu mukuru usanzwe ni (150-350) × 109 / L.Amashanyarazi afite umurimo wo gukomeza ubusugire bwinkuta zamaraso.Iyo umubare wa platel ugabanutse kugera kuri 50 × Iyo umuvuduko wamaraso uri munsi ya 109 / L, ihahamuka rito cyangwa umuvuduko wamaraso gusa birashobora gutera ibibara byamaraso kuruhu na subucosa, ndetse na purpura nini.Ni ukubera ko platine ishobora gutura kurukuta rwamaraso igihe icyo aricyo cyose kugirango yuzuze icyuho cyasizwe na selile endothelial selile, kandi irashobora guhurira mumyanya ndangagitsina ya endoteliyale, ishobora kugira uruhare runini mukubungabunga ubusugire bwimikorere ya endoteliyale cyangwa gusana ingirabuzimafatizo.Iyo hari platine nkeya, iyi mirimo iragoye kuyirangiza kandi hariho imyumvire yo kuva amaraso.Amaraso mu maraso azenguruka muri rusange ari "guhagarara".Ariko iyo imiyoboro yamaraso yangiritse, platine ikora binyuze muburyo bwo guhuza no gukora ibintu bimwe na bimwe bya coagulation.Amashanyarazi akora arashobora kurekura urukurikirane rwibintu bikenewe mugikorwa cya hemostatike no gukora imirimo yumubiri nka adhesion, guteranya, kurekura, na adsorption.

Platelet itanga Megakaryocyte nayo ikomoka kuri selile hematopoietic stem selile.Ingirabuzimafatizo ya Hematopoietic ibanza gutandukanya megakaryocyte progenitor selile, izwi kandi nka koloni ikora megakaryocyte (CFU Meg).Chromosomes muri nucleus ya progenitor selile icyiciro muri rusange ni ploidy.Iyo selile progenitor ari diploid cyangwa tetraploid, selile zifite ubushobozi bwo kwiyongera, iyi rero niyo ntambwe iyo imirongo ya Megakaryocyte yongera umubare wingirabuzimafatizo.Iyo selile ya megakaryocyte yarushijeho gutandukana muri 8-32 ploidy Megakaryocyte, cytoplazme yatangiye gutandukana hanyuma sisitemu ya Endomembrane irangira buhoro buhoro.Hanyuma, ibintu bya membrane bitandukanya cytoplazme ya Megakaryocyte mubice byinshi bito.Iyo buri selile itandukanijwe rwose, iba platel.Umwe umwe, platine igwa kuri Megakaryocyte ikanyura mu cyuho kiri hagati yingirabuzimafatizo ya endoteliyale yurukuta rwa sinus rwimitsi ikinjira mumaraso.

Kugira imiterere itandukanye yubudahangarwa.TPO ni glycoproteine ​​ikorwa cyane cyane nimpyiko, ifite uburemere bwa molekile hafi 80000-90000.Iyo platine mumaraso igabanutse, kwibumbira hamwe kwa TPO mumaraso biriyongera.Imikorere yibi bintu bigenga harimo: ① kuzamura synthesis ya ADN muri selile progenitor no kongera umubare wa polyploide selile;Gukangurira Megakaryocyte guhuza poroteyine;Ongera umubare rusange wa Megakaryocyte, bigatuma umusaruro wa platel wiyongera.Kugeza ubu, abantu bemeza ko ikwirakwizwa no gutandukanya Megakaryocyte bigengwa ahanini n’ibintu bibiri bigenga ibyiciro bibiri byo gutandukana.Izi mikorere zombi ni megakaryocyte Colony-itera imbaraga (Meg CSF) na Thrombopoietin (TPO).Meg CSF nikintu kigenga cyane cyane ikora kuri progenitor selile, kandi uruhare rwayo ni ugukwirakwiza ikwirakwizwa rya megakaryocyte progenitor.Iyo umubare rusange wa Megakaryocyte mu magufa ugabanutse, umusaruro wibi bintu byiyongera.

Nyuma ya platine yinjiye mumaraso, bafite imikorere yumubiri muminsi ibiri yambere, ariko impuzandengo yabo yo kubaho irashobora kuba iminsi 7-14.Mubikorwa bya physiologique hemostatike, platine ubwayo izasenyuka kandi irekure ibintu byose bikora nyuma yo guteranya;Irashobora kandi kwinjirira mumitsi ya endoteliyale.Usibye gusaza no kurimbuka, platine irashobora no gukoreshwa mugihe cyimikorere ya physiologique.Amaraso ashaje yibasiwe nintanga, umwijima, nibihaha.

1. Ibikorwa remezo bya platine

Mubihe bisanzwe, platine igaragara nka disiki ya convex nkeya kumpande zombi, impuzandengo ya diameter ya 2-3 μ m.Impuzandengo yikigereranyo ni 8 μ M3.Platelets ni selile nucleaux idafite imiterere yihariye munsi ya microscope optique, ariko ultrastructure irashobora kugaragara munsi ya microscope ya electron.Kugeza ubu, imiterere ya platine igabanijwemo mubice bikikije, agace ka gel gel, agace ka Organelle hamwe na sisitemu yihariye ya sisitemu.

Ubusanzwe platelet isanzwe iroroshye, hamwe nububiko buto bugaragara, kandi ni sisitemu ifunguye (OCS).Agace gakikije ubuso bwa platel kagizwe nibice bitatu: urwego rwinyuma, igice cyibice, hamwe nubutaka bwa submembrane.Ikoti igizwe ahanini na glycoproteine ​​zitandukanye (GP), nka GP Ia, GP Ib, GP IIa, GP IIb, GP IIIa, GP IV, GP V, GP IX, n'ibindi. kuri TSP, trombin, kolagen, fibrinogen, nibindi. Ni ngombwa ko platine igira uruhare mu kwanduza no gukumira indwara.Igice cya membrane, kizwi kandi nka plasma membrane, kirimo poroteyine zinjijwe muri lipide bilayeri.Umubare nogukwirakwiza ibyo bice bifitanye isano na platel adhesion hamwe na coagulation imikorere.Ibibyimba birimo Na + - K + - ATPase, ikomeza itandukaniro rya ion yibanze imbere no hanze yacyo.Agace ka submembrane gaherereye hagati yigice cyo hepfo yikibice no kuruhande rwa microtubule.Agace ka Submembrane karimo filaments ya submembrane na Actin, bifitanye isano no gufatira platine no guteranya.

Microtubules, microfilaments na submembrane filaments nayo ibaho mukarere ka sol gel ka platine.Ibi bintu bigize sisitemu ya skeleton no kwikuramo ya platine, bigira uruhare runini muguhindura platine, kurekura ibice, kurambura, no kwikuramo imyenda.Microtubules igizwe na Tubulin, ihwanye na 3% bya poroteyine zose.Igikorwa cabo nyamukuru nukugumana imiterere ya platine.Microfilaments ahanini irimo Actin, niyo proteine ​​nyinshi muri platine kandi ikagira 15% ~ 20% bya poroteyine zose.Submembrane filaments ahanini igizwe nibice bya fibre, bishobora gufasha poroteyine ya Actin-ihuza na Actin guhuza hamwe.Hateganijwe ko habaho Ca2 +, actin ikorana na prothrombine, kontinine, guhuza poroteyine, co actin, myosin, nibindi kugirango irangize imiterere ya platine, imiterere ya pseudopodium, kwikuramo selile nibindi bikorwa.

Imbonerahamwe 1 Platelet Membrane Glycoproteine

Agace ka Organelle nigice kibamo ubwoko bwinshi bwa Organelle muri platine, bigira ingaruka zikomeye kumikorere ya platine.Nubushakashatsi bwibanze mubuvuzi bwa kijyambere.Ibice byingenzi mubice bya Organelle nibice bitandukanye, nka α Ibice, ibice byuzuye （δ Ibice) na Lysosome （λ Ibice, nibindi, reba Imbonerahamwe 1 kugirango ubone ibisobanuro birambuye.α Granules ni ahantu ho kubika muri platine zishobora gusohora poroteyine.Hariho ibirenga icumi muri buri platine α Ibice.Imbonerahamwe 1 irerekana gusa ibice byingenzi ugereranije, kandi ukurikije ubushakashatsi bwumwanditsi, byagaragaye ko α Hariho urwego rurenga 230 rwibintu biva muri platine (PDF) biboneka muri granules.Ikigereranyo cyinshi α Ibice ni bito gato, bifite umurambararo wa 250-300nm, kandi muri buri platine hari ibice 4-8 byuzuye.Kugeza ubu, byagaragaye ko 65% ya ADP na ATP bibitswe mu bice byuzuye muri platine, naho 90% ya 5-HT mu maraso nabyo bibikwa mu bice byuzuye.Kubwibyo, ibice byuzuye nibyingenzi muguteranya platine.Ubushobozi bwo kurekura ADP na 5-HT nabwo bukoreshwa mubuvuzi kugirango dusuzume imikorere ya platelet.Byongeye kandi, aka karere karimo mitochondria na Lysosome, ari nacyo kigo cy’ubushakashatsi mu gihugu ndetse no hanze yacyo muri uyu mwaka.Igihembo cyitiriwe Nobel cya 2013 muri Physiology and Medicine cyahawe abahanga batatu, James E. Rothman, Randy W. Schekman, na Thomas C. S ü dhof, kubera kuvumbura amayobera y’uburyo bwo gutwara abantu.Hariho kandi imirima myinshi itazwi muri metabolism yibintu nimbaraga muri platine binyuze mumibiri idasanzwe na Lysosome.

Umwanya udasanzwe wa sisitemu urimo OCS hamwe na sisitemu yuzuye ya tubular (DTS).OCS ni uburyo bwo gutobora imiyoboro ikozwe nubuso bwa platine bwiroha imbere imbere ya platine, byongera cyane ubuso bwa platine ihura na plasma.Muri icyo gihe, ni umuyoboro udasanzwe wibintu bitandukanye byinjira muri platine no kurekura ibintu bitandukanye bigize platine.Umuyoboro wa DTS ntabwo uhujwe n’isi kandi ni ahantu ho gusanisha ibintu biri mu ngirabuzimafatizo.

2. Imikorere ya Physiologique ya platine

Igikorwa nyamukuru cyimikorere ya platine ni ukwitabira hemostasis na trombose.Ibikorwa bikora bya platine mugihe cya hemostasis physiologique irashobora kugabanywamo ibice bibiri: hemostasis yambere na hemostasis ya kabiri.Amashanyarazi afite uruhare runini mubyiciro byombi bya hemostasis, ariko uburyo bwihariye bukora buracyatandukanye.

1) Imikorere yambere ya hemostatike ya platine

Trombus ikorwa mugihe cya hemostasis yambere ni trombus yera cyane, kandi reaction yibikorwa nka platelet adhesion, deformation, kurekura, hamwe no guteranya nuburyo bukomeye mubikorwa byambere bya hemostasis.

I. Igisubizo cya platel

Gufatanya hagati ya platine no hejuru ya platine bita platel adhesion, iyo ikaba ari intambwe yambere yo kugira uruhare mu myitwarire isanzwe ya hemostatike nyuma yo kwangirika kw'imitsi n'intambwe ikomeye muri trombose.Nyuma yo gukomeretsa kw'imitsi, platine inyura muri ubu bwato ikorwa hejuru yumubiri munsi ya endotelium yimitsi hanyuma igahita ifatira kumitsi ya kolagen yagaragaye aho yakomeretse.Ku minota 10, platine yabitswe yabantu yageze ku giciro cyayo kinini, ikora amaraso yera.

Ibintu nyamukuru bigira uruhare mugikorwa cyo gufatira platine harimo platelet membrane glycoprotein Ⅰ (GP Ⅰ), von Willebrand factor (vW factor) na kolagen mubice bya subendothelia.Ubwoko bwingenzi bwa kolagene bugaragara kurukuta rwamaraso ni ubwoko bwa I, III, IV, V, VI, na VII, muribwo bwoko bwa I, III, na IV kolagen aribyingenzi muburyo bwo gufata platine mubihe bitemba.Ikintu cya vW ni ikiraro gihuza guhuza platine kugirango wandike ubwoko bwa I, III, na IV, hamwe na reseptor ya glycoproteine ​​GP Ib kuri membrane ya platine ni urubuga nyamukuru rwo guhuza platine.Byongeye kandi, glycoproteine ​​GP IIb / IIIa, GP Ia / IIa, GP IV, CD36, na CD31 kuri membrane ya platelet nayo igira uruhare mu gufatira hamwe na kolagen.

II.Igiteranyo cya platel reaction

Ikintu cya platine gifatana byitwa guteranya.Igiteranyo cyo guterana kibaho hamwe na reaction ya adhesion.Imbere ya Ca2 +, platelet membrane glycoprotein GPIIb / IIIa hamwe na fibrinogen igiteranyo cyatatanye hamwe.Igiteranyo cya platel gishobora guterwa nuburyo bubiri butandukanye, bumwe ni imiti itera imiti itandukanye, naho ubundi biterwa nihungabana ryogosha mugihe ibintu bitemba.Mugutangira kwegeranya, platine ihinduka kuva mumiterere ya disiki igahinduka imiterere ya serefegitura kandi ikagaragaza ibirenge bya pseudo bisa nkamahwa mato;Muri icyo gihe, platine degranulation bivuga kurekura ibintu bikora nka ADP na 5-HT byari byarabitswe mbere mubice bito.Isohora rya ADP, 5-HT hamwe numusaruro wa Prostaglandine ni ngombwa cyane muguteranya.

ADP nikintu cyingenzi cyo gukusanya platine, cyane cyane ADP ya endogenous ADP yasohotse muri platine.Ongeramo umubare muto wa ADP (kwibanda kuri 0.9) kuri platine ihagarikwa μ Munsi ya mol / L), irashobora gutera vuba guteranya platine, ariko vuba depolymerize;Niba ibipimo biciriritse bya ADP (1.0) byongeweho μ Hafi ya mol / L, icyiciro cya kabiri cyo guterana kidasubirwaho kibaho nyuma yigihe cyo kurangiza icyiciro cya mbere cyo guteranya hamwe nicyiciro cya depolymerisation, biterwa na ADP endogenous ADP yarekuwe na platine;Niba umubare munini wa ADP wongeyeho, biratera byihuse guteranya bidasubirwaho, byinjira muburyo bwa kabiri bwo guteranya.Ongeraho dosiye zitandukanye za trombine muguhagarika platine birashobora kandi guteranya platine;Kandi bisa na ADP, nkuko dosiye igenda yiyongera buhoro buhoro, igiteranyo gishobora guhinduka kuva mugice cya mbere gusa kugeza kugaragara mubyiciro bibiri byo guteranya, hanyuma bikinjira muburyo bwa kabiri bwo guteranya.Kubera ko guhagarika irekurwa rya ADP ya endogenous hamwe na adenosine bishobora kubuza kwegeranya platine iterwa na trombine, byerekana ko ingaruka za trombine zishobora guterwa no guhuza trombine na reseptor ya trombine kuri membrane ya selile, bigatuma ADP irekurwa.Kwiyongera kwa kolagen birashobora kandi gutera platel guteranya muguhagarikwa, ariko guteranya bidasubirwaho mugice cya kabiri mubisanzwe bizwi ko biterwa no kurekura endogenous ADP yatewe na kolagen.Ibintu bishobora gutera guteranya platine birashobora kugabanya cAMP muri platine, mugihe ibibuza guteranya platel byongera cAMP.Kubwibyo, kuri ubu abantu bemeza ko kugabanuka kwa cAMP bishobora gutera kwiyongera kwa Ca2 + muri platine, bigatera irekurwa rya ADP endogenous.ADP itera gukusanya platine, bisaba ko habaho Ca2 + na fibrinogen, hamwe no gukoresha ingufu.

Uruhare rwa platel Prostaglandin Fosifolipide ya plasma plasma membrane irimo aside Arachidonic, naho selile ya platine irimo aside Fosifatique A2.Iyo platine ikorewe hejuru, Phospholipase A2 nayo irakora.Munsi ya catalizike ya Fosifolipase A2, aside Arachidonic itandukanijwe na fosifolipide muri plasma membrane.Acide ya Arachidonic irashobora gukora umubare munini wa TXA2 munsi ya catalizike ya platelet cyclooxygenase na synthase ya Thromboxane.TXA2 igabanya cAMP muri platine, bikaviramo gukomera kwa platel hamwe ningaruka za vasoconstriction.TXA2 nayo ntigihungabana, nuko ihita ihinduka TXB2 idakora.Byongeye kandi, selile zisanzwe zifata imitsi zirimo synthase ya prostacyclin, ishobora guhagarika umusaruro wa prostacyclin (PGI2) ivuye muri platine.PGI2 irashobora kongera cAMP muri platine, bityo igira ingaruka zikomeye zo kubuza platel hamwe na Vasoconstriction.

Adrenaline irashobora kunyuzwa muri α 2. Guhuza reseptor ya Adrenergique birashobora gutera biphasic platelet yegeranya, hamwe na (0.1 ~ 10) μ Mol / L.Thrombin yibitekerezo bike (<0.1 μ Kuri mol / L, icyiciro cya mbere cyo guteranya platine giterwa ahanini na PAR1; Mugihe cyinshi (0.1-0.3) μ Kuri mol / L, icyiciro cya kabiri cyo guteranya gishobora guterwa na PAR1 na PAR4 .Ibitera imbaraga zo guteranya platine kandi harimo ibintu bifasha gukora platine (PAF), kolagen, vW ibintu, 5-HT, nibindi. Igiteranyo cya platel nacyo gishobora guterwa nuburyo bwimikorere idafite imashini itera. Ubu buryo bukora cyane cyane muri trombose arterial, nka aterosklerose.

III.Platelet irekura reaction

Iyo platine ikozwe na physiologique, ibikwa mubice byimbitse α Ikintu cyibintu byinshi mubice na lysosomes birukanwa muri selile byitwa kurekura.Imikorere ya platine hafi ya yose igerwaho binyuze mubinyabuzima bwibintu byakozwe cyangwa birekuwe mugihe cyo kurekura.Inducers hafi ya zose zitera platelet yegeranya irashobora gutera kurekura reaction.Kurekura reaction mubisanzwe bibaho nyuma yicyiciro cya mbere cyo guteranya platine, kandi ibintu byasohowe nigisubizo cyo kurekura bitera icyiciro cya kabiri.Inducers zitera kurekura zirashobora kugabanywa mubice:

i.Inducer idakomeye: ADP, adrenaline, Norepinephrine, vasopressine, 5-HT.

ii.Ibitera hagati: TXA2, PAF.

iii.Inducers zikomeye: trombine, enzyme ya pancreatic enzyme, kolagen.

2) Uruhare rwa platine muguhuza amaraso

Platelets igira uruhare runini muburyo butandukanye bwo kwifata binyuze muri fosifolipide na membrane glycoproteine, harimo adsorption no gukora ibintu bya coagulation (ibintu IX, XI, na XII), gushiraho coagulation iteza imbere ibigo hejuru ya fosifolipide, no guteza imbere prothrombine.

Indwara ya plasma hejuru yubuso bwa platine ihuza ibintu bitandukanye bya coagulation, nka fibrinogen, V, ikintu XI, XIII, nibindi X α, α na PF3 byombi biteza imbere amaraso.PF4 irashobora gutesha agaciro heparin, mugihe PF6 ibuza fibrinolysis.Iyo platine ikorewe hejuru, irashobora kwihutisha gahunda yo gukora ibintu bya coagulation XII na XI.Ubuso bwa fosifolipide (PF3) butangwa na platine bivugwa ko bwihutisha imikorere ya prothrombine inshuro 20000.Nyuma yo guhuza ibintu Xa na V hejuru yiyi fosifolipide, birashobora kandi gukingirwa ingaruka zibuza antithrombine III na heparin.

Iyo platine yegeranye kugirango ikore trombus hemostatike, inzira ya coagulation imaze kuba mugace, kandi platine yerekanaga ibintu byinshi bya fosifolipide, bitanga uburyo bwiza cyane bwo gukora ibintu X na prothrombine.Iyo platine ikanguwe na kolagen, trombine cyangwa kaolin, Sphingomyelin na Phosphatidylcholine hanze yimbere ya platelet ihinduka hamwe na fosifatique Ethanolamine na fosifatidylserine imbere, bigatuma kwiyongera kwa fosifatique Ethanolamine na fosifatidylserine hejuru ya membrane.Amatsinda ya fosifatique yavuzwe hejuru hejuru ya platine agira uruhare mukurema imitsi hejuru ya membrane mugihe cyo gukora platine.Imitsi iratandukana kandi ikinjira mumaraso kugirango ikore microcapsules.Imitsi na microcapsules bikungahaye kuri fosifatidylserine, ifasha mu guteranya no gukora prothrombine kandi ikagira uruhare mu gikorwa cyo guteza imbere amaraso.

Nyuma yo guteranya platine, α yayo Kurekura ibintu bitandukanye bya platine mubice bitera kwimura no kwiyongera kwa fibre yamaraso, kandi igatega izindi selile zamaraso kugirango zibe uturemangingo.Kubwibyo, nubwo platine igenda isenyuka buhoro buhoro, emboli hemostatike irashobora kwiyongera.Amashanyarazi asigaye mu maraso afite pseudopodiya igera mu miyoboro y'amaraso.Poroteyine zandura muri iyi platine zandura, bigatuma amaraso atembera, asohora serumu ahinduka icyuma gikomeye cya hemostatike, gifunga neza icyuho cyimitsi.

Iyo ukora platine na sisitemu ya coagulation hejuru, nayo ikora sisitemu ya fibrinolytike.Plasmin nuwayikoresheje ikubiye muri platine izasohoka.Isohora rya serotonine mu maraso no mu maraso birashobora kandi gutuma selile endoteliyale irekura abayikora.Ariko, kubera gusenyuka kwa platine no kurekura PF6 nibindi bintu bibuza protease, ntabwo bigira ingaruka kubikorwa bya fibrinolytique mugihe cyo gushiraho amaraso.

Ibiri muri iyi ngingo byongeye gusubirwamo, kandi ntidutanga ingwate iyo ari yo yose cyangwa yerekana ko ari ukuri, kwiringirwa cyangwa kuzuza ibikubiye muri iyi ngingo, kandi ntabwo dushinzwe ibitekerezo by'iyi ngingo, nyamuneka ubyumve.）