Imethylene blue yokwenzakala kobuchopho: ukuqonda ubungqina bophando lwangaphambi kwezilingo ebantwini

Ukubethwa entloko, ukuvaleka komthambo wegazi, nesifo esibangela ukuwohloka okucothayo kweeseli zemithambo-luvo zinokuphela ngengxaki efanayo: ubuchopho abusasenawo amandla okwenza umsebenzi wabo. Esi siphumo sifanayo sesona sizathu sokuba ikhompawundi enye iqhubeke ivela kuncwadi lophando lwazo zontathu. Kodwa isiphumo esifanayo asithethi ingcamango efanayo. Unyango olunikwa ngaphambi kokwenzakala, unyango olunikwa kwiyure elandelayo, nonyango oluneziphumo ezilinganiswa kwiinyanga kamva luvavanya iingcamango ezahlukeneyo, nokuba isirinji inolwelo olufanayo oluluhlaza okwesibhakabhaka.

Eli nqaku lilandela inxalenye yolu ncwadi ephathelele ukwenzakala. Lihlolisisa okuthethwa yimethylene blue yokwenzakala kobuchopho kuvavanyo lwezilwanyana, lahlula ukwenzakala okubangelwa yintlupheko kwistrowukhi nakukuwohloka okungapheliyo kweeseli zemithambo-luvo, lize libonise ukuba kutheni ixesha lokunikwa kwedosi lichaza uninzi lweeyantlukwano phakathi kwezifundo.

Iintlobo ezintathu zokwenzakala, ukusilela kwamandla okukodwa

Indlela yokusebenza edibanisa ezi modeli ikwiimitochondria. Ngokuqhelekileyo, ii-elektroni zihamba kwikhonkco lothutho lwee-elektroni ukuze kuveliswe i-ATP, yaye ikhonkco elisebenza kakuhle ligcina iimolekyuli zeoksijini ezisebenzayo phantsi kolawulo. Emva kokwenzakala, iindawo ezithile zekhonkco ziyasilela, imveliso ye-ATP iyehla, kuze kunyuke ukuveliswa kweeradikali ezikhululekileyo. Uhlalutyo luka-2018 lweMolecular Neurobiology luchaza imethylene blue njengomnye umthwali wee-elektroni: yamkela ii-elektroni kwi-NADH ize izidlulisele kwi-cytochrome c, nto leyo enyusa umsebenzi wekhompleksi IV ize ibuyisele ukuveliswa kwe-ATP naxa inxalenye yokuqala yekhonkco yonakele.

Amanani axeliweyo acacile. Kumalungiselelo eeseli nezilayi zezicubu, umsebenzi wekhompleksi IV wenyuka nge-30 ukuya kwi-100 pesenti, ngoxa ukusetyenziswa kweoksijini kwenyuka ngokuhambelanayo, nto leyo ebonisa ukuba ii-elektroni ezongezelelekileyo zenza umsebenzi oluncedo kunokuba ziphume njengeeradikali. Kwimodeli yestrowukhi kwiimpuku, ukuveliswa kwe-ATP kummandla ochaphazelekayo kwakumalunga ne-30 pesenti ngaphezulu kwiiyure ezingama-24 emva konyango kunakwizilwanyana ezinganyangwanga. Uhlalutyo luka-2022 lweBiochemistry (Moscow) longeza iziphumo ezilandela oko: uxinzelelo lwe-oxidative oluncinane, ukudumba okuncinane kwezicubu zemithambo-luvo, ukufa okucwangcisiweyo kweeseli okuncinane, kunye neempembelelo kwi-monoamine oxidase, kwi-nitric oxide synthase, ekuvelisweni kweemitochondria, ekuzicoceni kweeseli, nasekuhlanganeni kweeproteni ezisongeke ngendlela engachanekanga.

Ngoko ingcamango ilula. Ukwenzakala kuthintela indlela eqhelekileyo yee-elektroni, yaye imethylene blue inika enye indlela. Konke okulandelayo kungumbuzo wokuba loluphi uhlobo lokwenzakala, inikwe nini, yaye ilinganiswe njani.

Ukwenzakala ngenxa yentlupheko akusiso istrowukhi

Kwimodeli yokwenzakala kobuchopho okubangelwa yintlozi yokubethwa, amandla asebenza ngequbuliso. Umonakalo wokuqala ubangelwa ngamandla omzimba: izicubu ziyakrazuka, imithambo yegazi iyagqabhuka, yaye umqobo ophakathi kwegazi nobuchopho uyavuleka kwimizuzu nje. Into enokuchatshazelwa yimethylene blue liliza lesibini lomonakalo elilandela kwiiyure neentsuku, njengoko iimitochondria kwizicubu ezisindileyo zisilela, ukusabela kokudumba kusanda, kuze kuqokelelane ulwelo. Imilinganiselo yeziphumo kwezi zifundo ibonisa olo landelelwano: umthamo wendawo eyonakeleyo, isiqulatho samanzi ebuchotsheni, ukusinda kweeseli zemithambo-luvo kufuphi nendawo yokubethwa, nokuziphatha kamva okufana nokuchacha kwentshukumo okanye ukufunda indlela kwilabhirinti.

Kwimodeli yestrowukhi okanye yokungafumani gazi kobuchopho bonke, indlela okwenzeka ngayo umonakalo yahlukile. Ukuhamba kwegazi kuyayeka, ukusilela kwamandla kulandela kwimizuzu nje, yaye ukubuyela kokuhamba kwegazi kuzisa umonakalo wako wokubuyiselwa kwegazi. Apha ukunikwa kwedosi kulungelelaniswa nesiganeko somthambo wegazi, ngokufuthi kwimizuzu nje yokuvaleka okanye yokubuyiselwa kwegazi, yaye imilinganiselo yeziphumo ilinganisa oko kwenzeka kwizicubu ngexesha elifutshane, ukusuka kwiiyure ukuya kusuku okanye ezimbini: ubungakanani bendawo yezicubu ezifileyo ngenxa yokungafumani gazi, ukuhamba kwegazi, nokuchacha kokuqala kokusebenza. Enye indlela esetyenziswa kuncwadi lwesifo sestrowukhi lunyango lwangaphambili, apho izilwanyana zinikwa idosi ngaphambi kokuvalwa komthambo wegazi. Oku kuvavanya uthintelo ngendlela ekungekho luvavanyo lokwenzakala kwentloko olunokuyiphinda ebantwini ngokuhambelana nemigaqo yokuziphatha.

Iziphumo zestrowukhi zezona zinamandla kuncwadi lokwenzakala, yaye ziquka nesona siphumo sicacileyo sokungabikho kwempembelelo. Iimpuku ezanikwa imethylene blue xa kubuyiselwa ukuhamba kwegazi emva kweyure enye yokuvalwa komthambo ophakathi wobuchopho zaba neendawo zezicubu ezifileyo ezincinci nge-30 pesenti ngosuku 2, yaye kwasindiswa inxalenye enkulu ngakumbi yombindi osengozini nommandla owujikelezileyo (Shen, 2013). Isifundo sokuvaleka okusisigxina safumanisa ukuba izicubu ezisengozini zajika zaba zizicubu ezifileyo ngokucothayo, kodwa umthamo wokugqibela wezicubu ezifileyo kwiiyure ezingama-24 awuzange unciphise kuyo nayiphi na kwezi dosi zimbini zavavanywayo (Rodriguez, 2014). Isifundo sesithathu sokuvaleka sawunciphisa ubungakanani bendawo yezicubu ezifileyo malunga nesiqingatha kwidosi ephakathi, saza sabhala ngokuthe ngqo ngesakhiwo esincinane seemitochondria nangokususwa kwazo ngokuzicoca kweseli kubuchopho obungafumani gazi. Sikwaxele iinkcukacha ezichasene nokulindelekileyo: ukufa okucwangcisiweyo kweeseli okulinganisiweyo kwenyuka njengoko ukufa kweeseli ngenxa yomonakalo kwehla (Di, 2015). Kwaye xa ubuchopho bonke bungafumani gazi, ukufakwa okuqhubekayo kwedosi ephantsi kwabuyisela umsebenzi we-cytochrome c oxidase, amanqanaba e-ATP, nomahluko wombane kwinwebu yeemitochondria kummandla we-CA1 wehippocampus osengozini, kwagcina ezo seli zemithambo-luvo, kwaza kwakhusela inkumbulo yendawo (Lu, 2016). Loo mlinganiselo we-CA1 ufanele ukuqwalaselwa: yidatha ethe ngqo ye-ATP neyekhonkco lokuphefumla evela ngaphakathi kobuchopho obonzakeleyo, nto leyo uncwadi lwe-TBI oludla ngokuyiqikelela kunokuba luyilinganise.

Ukuwohloka okungapheliyo kweeseli zemithambo-luvo kwahlukile kuzo zombini. Iimodeli zezifo ze-Alzheimer, Parkinson ne-Huntington zinika izilwanyana iidosi kangangeeveki okanye iinyanga, zize zilinganise ukuhlanganisana kweeproteni, ukuphathwa kwedopamine, okanye ukuhla kancinci kwamandla okuqonda. Le milinganiselo yeziphumo iphantse ingabinanto ifana ngayo nendawo eyonakeleyo elinganiswa kwiintsuku emva kokubethwa. Abafundi abathatha isiphumo kolunye udidi basise kolunye badlulisa oko kufunyenweyo kumda olungazange luwuwele uvavanyo. Isikhokelo sethu soncwadi lokuwohloka kweeseli zemithambo-luvo sigcina ezo zifundo zamaxesha amade kumxholo wazo, yaye uthelekiso nobungqina obuphathelele istrowukhi kuphela lwahlula ngokweenkcukacha izicwangciso zokuvalwa kwemithambo yegazi kwezokubethwa.

Oko kwenziwa ngokwenene ziimodeli ze-TBI

Akukho silingo sebantwini semethylene blue yokwenzakala kobuchopho okubangelwa yintlozi yokubethwa esipapashiweyo. Lonke uphando lwe-TBI lwenziwe kwizilwanyana, ubukhulu becala iimpuku ezinkulu nezincinci, yaye lugxile kwiqela elincinane leemvavanyo ezifanele ukukhankanywa, kuba iinkcukacha zazo zahluka ngeendlela ezidla ngokufihlwa zizishwankathelo.

Isifundo sokuqala sokubethwa okulawulwayo kwecortex sanika iimpuku i-1 mg/kg emthanjeni kwiyure enye emva kokubethwa okungephi, saza sanika i-0.5 mg/kg kwiiyure ezintathu (Watts, 2014). Umthamo wendawo eyonakeleyo obonwe nge-MRI wahlala usezantsi kwizilwanyana ezanyangwayo kwiiveki ezimbini zokulandelela. Ukunyathela kakubi kuvavanyo lokuhamba kwehla ngokuphawulekayo ngeentsuku 1, 2, no-7 kodwa hayi ngosuku 14. Xa kujongwe ngemikroskopu ngosuku 14, iiseli zemithambo-luvo ezaziswohloka kwicortex eyonakeleyo zabalwa zingama-270 xa kuthelekiswa nama-368 kwindawo nganye yokujonga, yaye ukudayeka okungaqhelekanga kweNissl kwakungama-41 xa kuthelekiswa nama-73. Ngamanye amazwi, kwakukho ukhuseleko lwakwangoko, kodwa umahluko ongcono ekuziphatheni wawuncipha kwiveki yesibini.

Uvavanyo lokwenzakala okusasazekileyo lwasebenzisa ukubethwa ngoxinzelelo lolwelo kumgca ophakathi kwiimpuku ezincinci nedosi enye ye-2 mg/kg emthanjeni ngaphakathi kwesiqingatha seyure (Fenn, 2015). Izilwanyana ezanyangwayo zabonisa ukuveliswa okuncinane kweemveliso zemfuza ezinxulumene nokudumba, iiseli ezimbalwa zemicroglia ezikhuthaza ukudumba, ukuqokelelana kolwelo okubonakala kuncinane, nokungabikho kokuziphatha okufana nokudakumba ngosuku 7. Iziphumo zokungabikho kwempembelelo zibaluleke ngokulinganayo: ukwenzakala ngokwako kwanyusa amanzi ebuchotsheni kancinane kuphela, yaye imethylene blue ayizange ithintele ukwehla kobunzima bomzimba okanye ilungise ukunqongophala kokulungelelanisa iintshukumo. Ukunciphisa ukusabela kokudumba akufani nokukhusela ngokupheleleyo.

Izifundo ezibini kwiimpuku ezincinci zasebenzisa ishedyuli efanayo, i-1 mg/kg kwiyure enye, i-0.5 mg/kg kwiiyure ezintandathu, kwaza kwalandela ukunikwa kwedosi yonke imihla kangangeentsuku ezintathu, zaza zandisa ukuqonda indlela yokusebenza. Kwimodeli yokubethwa kwecortex, unyango lwanciphisa umthamo wendawo eyonakeleyo kwiiyure ezingama-24, kwiiyure ezingama-72, nangosuku 14, ngoxa lugcina iiseli zemithambo-luvo luze lunyuse iziphawuli zokuzicoca kweeseli (Zhao, 2016). Kwimodeli yokubethwa ngoxinzelelo lolwelo, lwanciphisa ukufa okucwangcisiweyo kweeseli zemithambo-luvo, lwaqinisa umqobo wegazi nobuchopho owawuvuza, lwaza lwaphucula amanqaku okusebenza kwemithambo-luvo kwiiveki ezimbini (Shen, 2019). Kodwa isiqulatho samanzi ebuchotsheni asizange sibonise mahluko kwiiyure ezingama-72 kwisifundo sikaZhao, yaye ukusebenza kuvavanyo lwentonga ejikelezayo akuzange kubonise mahluko ngeentsuku 1 no-3 kwisifundo sikaShen. Imilinganiselo yendawo eyonakeleyo neyokusinda kweeseli yatshintsha; eyokudumba neyentshukumo yokuqala yayingasoloko ilandela.

Uvavanyo olubalaseleyo ngokwexesha lelokunikwa kwedosi okulibazisiweyo (Watts, 2016). Kusetyenziswa imodeli efanayo yokubethwa, idosi yokuqala ayizange inikwe de kwadlula iiyure ezingama-24 emva kokwenzakala. Ngosuku 2 iqela elanikwa idosi emva kwexesha labonisa ukuncipha kwendawo eyonakeleyo okuthelekiseka nokwezilwanyana ezanyangwa kwiiyure zokuqala, yaye oko kuncipha kwaqhubeka ngeentsuku 7 no-14. Uphawu lokuphucuka kokuziphatha lwalubuthathaka ngakumbi: ukuphucuka kokunyathela kakubi kwiqela elanikwa idosi emva kwexesha kwakuyindlela ebonakalayo kodwa engabalulekanga ngokwezibalo. Ilabhoratri enye, imodeli enye, ixesha elinye leeyure ezingama-24. Obo bubungqina bokwenene bokuba ixesha lokungenelela lidlulela ngaphaya kweeyure zokuqala, yaye ikwabo bonke ubungqina baloo ngcamango. Qaphela umgibe wegama elithi kulibazisiwe kwezinye iindawo: uthotho lwezifundo zaseRashiya olunesihloko esiphathelele ukhuseleko olulibazisiweyo lweeseli zemithambo-luvo lwanika idosi kwimizuzu engama-30, lwaza lwasebenzisa igama elithi kulibazisiwe ukubhekisa kwiziphumo ezihlala ixesha elide, hayi ekuqaliseni emva kwexesha.

Isifundo esincinane sokwenzakala kwindawo ethile kwiimpuku sigqibezela umfanekiso wexesha sisuka kwelinye icala: ukunikwa kwedosi kanye ngaphambi kokwenzakala nokunikwa kwayo kwimizuzu engama-30 emva koko kokubini kwanciphisa ukungasebenzi kakuhle kwamalungu omzimba (Stelmashook, 2019). Unyango lwangaphambili lusebenza elabhoratri kanye ngenxa yokuba ilabhoratri iyalicwangcisa ixesha lokwenzakala.

Ukuqwalasela idosi ngokungqongqo kubalulekile apha. Uhlalutyo luchaza iidosi eziphantsi njengezikhuthaza ukuphefumla kweemitochondria, neziphezulu njengezikuthintelayo, le ndlela inamanqanaba amabini efanayo ibonwa kuyo yonke inzululwazi yokusebenza kwemethylene blue. Yiyo loo nto iziphumo zingenakufundwa ngokungathi imethylene blue eninzi ithetha ukuchacha okungakumbi. Isifundo ngasinye sivavanya indawo enye kwigophe. Ingcaciso yempendulo kwidosi ilandela elo gophe kwiimodeli ezahlukeneyo, yaye inkcazelo yokhuseleko neziphumo ebezingalindelekanga ichaza oko kwenziwa ziidosi eziphezulu endaweni yoko.

Funda loo theyibhile ngokuthelekisa imiqolo: ikhompawundi enye, amaxesha amathathu ahlukeneyo. Uthintelo lukumqolo ophakathi, unyango olukhawulezileyo kweyokuqala emibini, neziphumo ezibonakala kamva kweyokuqala neyesithathu.

Uthintelo, unyango olukhawulezileyo, iziphumo ezibonakala kamva

Uthintelo lelona bango kulula ukuliqonda kakubi. Kwiimodeli zokungafumani gazi, izilwanyana ezinikwa idosi ngaphambi kokuvalwa komthambo wegazi ziqhuba ngcono, yaye eso siphumo ngamanye amaxesha sicatshulwa ngokungathi imethylene blue ikhusela nabuphi na ubuchopho kuwo nawuphi na umonakalo wexesha elizayo. Asibonisi nto injalo. Sibonisa ukuba iimitochondria ezilungiselelwe ngenye indlela yee-elektroni zinyamezela ngcono ukuphazamiseka okucwangcisiweyo kokuhamba kwegazi. Akukho mntu ucwangcisa ukwenzakala kwentloko.

Unyango olukhawulezileyo kulapho ubungqina be-TBI bugxile khona. Ukunikwa kwedosi kwiiyure emva kokubethwa kujolise kulandelelwano lomonakalo wesibini ngoxa lusaqhubeka: ukusilela kwamandla, uxinzelelo lwe-oxidative, ukusabela kokudumba, nokuqokelelana kolwelo. Imilinganiselo yendawo eyonakeleyo nokuqokelelana kolwelo ephucukayo apha iyimiphumo yokwenene yonyango, kodwa lunyango lwenkqubo eqhubekayo, hayi ukubuyiselwa kwezicubu ezikrazukileyo.

Iziphumo ezibonakala kamva yingcamango yesithathu. Ukuziphatha okulinganiswa kwiiveki emva kokwenzakala, okanye ukuphathwa kweeproteni okulinganiswa kwiinyanga zokusebenzisa imodeli yokuwohloka, kuphendula ukuba ukhuseleko lwakwangoko lwaqhubeka na okanye iinkqubo ezicothayo zatshintsha indlela yazo. Indawo eyonakeleyo encinci kwiiyure ezingama-24, indlela yokuphucuka kokuziphatha engabalulekanga ngokwezibalo emva kwedosi elibaziswe ngeeyure ezingama-24, nokuphucuka kuvavanyo lwelabhirinti kwiinyanga zokunikwa kwedosi okuqhubekayo ngamabango amathathu ahlukeneyo afuna ubungqina obahlukeneyo, yaye okwangoku lelokuqala kuphela elihlangabezana noko kufunekayo ngaphezu kwesihlandlo esinye.

Oko obu bungqina bungenakukubonisa

Isiphumo ngasinye esingasentla sinomda ofanayo. Iimitochondria zeempuku zisabela kwimethylene blue ngeendlela ezinokufana nezeemitochondria zabantu, kodwa impuku enikwa idosi emthanjeni kwimizuzu emva kokubethwa okulungelelaniswe ngokuchanekileyo ayifani nomntu ofika kwisebe likaxakeka kwiiyure emva kokuwa. Ukusetyenziswa kwe-anesthesia, ubuzaza bokwenzakala obulawulwayo, izilwanyana eziselula ezisempilweni, nexesha elifutshane lokulandelela zonke zinciphisa oko kunokudluliselwa ebantwini. Akukho sifundo semethylene blue sokwenzakala ngenxa yogqabhuko-dubulo konke konke, ngoko uhlobo lokwenzakala olubaluleke kakhulu kubafundi basemkhosini lulo olunobungqina obuncinane kakhulu.

Kananjalo akukho ndlela yokuguqulela iidosi zezilwanyana kwiidosi zabantu inikelwayo apha. Uncwadi lwezilwanyana lusebenzisa ukunikwa emthanjeni nangaphakathi kumngxuma wesisu ngeedosi ezikhethelwe ulawulo lovavanyo, hayi amathontsi aselwa ngomlomo athengiswa ezivenkileni. Akukho nto kwezi zifundo emisela isicwangciso sokusetyenziswa ebantwini, yaye akukho nto apha ivavanya imethylene blue kunye nonyango oluqhelekileyo lokwenzakala kwentloko.

Ngoko isishwankathelo esinyanisekileyo singena kumhlathi omnye. Kwiimpuku, imethylene blue enikwa kufutshane nexesha lokwenzakala kobuchopho okubangelwa kukubethwa okanye kukungafumani gazi igcina ukuveliswa kwamandla ziimitochondria, yaye oko kugcinwa kulandelwa ziindawo zomonakalo ezincinci namanqaku angcono okuchacha. Isifundo esinye sokubethwa sagcina inxalenye yempembelelo kwindawo eyonakeleyo xa idosi yokuqala ilibaziswe ngeeyure ezingama-24. Akukavavanywa ukuba nayiphi na kwezi zinto iyenzeka na kubuchopho babantu obonzakeleyo, yaye uncwadi lwe-TBI nolwestrowukhi luvavanya amaxesha ahlukeneyo ngokusebenzisa imilinganiselo yeziphumo eyahlukeneyo. Nabani na othengisa ukuqiniseka esekelwe kobu bungqina wongeza isithako esingazange sibe khona kwiimvavanyo.