ATP ndi methylene blue: kodi oxygen yambiri imatanthauza mphamvu zambiri?

Mitochondrion yopatukana ndi selo ili m'chipinda choyesera chokhala ndi zinthu zopangira mphamvu koma mulibe ADP. Imagwiritsa ntchito oxygen pang'onopang'ono. Mukathira ADP, kugwiritsa ntchito oxygen kumakwera kangapo. Mukadikira mpaka ADP itatha, kugwiritsa ntchito oxygen kumatsikanso. Zinthu zopangira mphamvu sizinasinthe. Chinasintha ndi kufunika kwa ATP kokha.

Zochitika zochepazi zikufotokoza kusiyana konse kumene nkhaniyi ikunena. Kugwiritsa ntchito oxygen kumayeza liwiro limene maelekitironi amayendera m'ndandanda wa kupuma kwa maselo kupita ku oxygen. Kupanga ATP kumayeza kuchuluka kwa mphamvu za kuyenda kumeneko zimene zimasungidwa monga mphamvu zogwiritsidwa ntchito. Zinthu ziwirizi zimadalira sitepe yapakati imodzimodzi: kusiyana kwa mapulotoni mbali ziwiri za nembanemba yamkati ya mitochondrion. Chilichonse chimene chimasintha kulimba kwa kulumikizana pakati pa kusiyana kumeneku ndi kupanga ATP chingachititse zinthu ziwirizi kusintha mosiyana. Methylene blue imatithandiza kumvetsa zimenezi chifukwa yasonyeza zonse ziwiri: kuwonjezera kugwiritsa ntchito oxygen pamodzi ndi ATP m'masampulo ena, komanso kuwonjezera kugwiritsa ntchito oxygen pamene ATP sikwera kapena imatsika m'masampulo ena.

Owerenga amene akufuna kuyamba ndi kumvetsa bwino njira yonse yopatsirana maelekitironi angayambe ndi mmene methylene blue imanyamulira maelekitironi m'ndandanda wa kupuma kwa maselo. Amene akufuna kumvetsa mawu a m'mayesero oyambirira a oxygen angawerenge zimene miyezo yoyambirira ya kupuma kwa maselo inasonyezadi.

Kupuma kwa maselo, ATP, ndi kusiyana kwa mapulotoni pakati pawo

Maelekitironi ochokera ku NADH ndi FADH2 amalowa m'ndandandawu pa complex I ndi II, amadutsa mu complex III kupita ku cytochrome c, kenako amadutsa mu complex IV kupita ku oxygen. Mphamvu zotulutsidwa pa complex I, III, ndi IV zimapopa mapulotoni kuchokera m'kati mwa mitochondrion, motchedwa matrix, kupita m'malo apakati pa nembanemba ziwiri. Kusiyana kumeneku kwa mphamvu ya magetsi ndi asidi ndi kumene kumapereka mphamvu yoyendetsa mapulotoni. Mbali yake ya magetsi, kusiyana kwa mphamvu ya magetsi pa nembanemba, nthawi zambiri ndiyo yaikulu kwambiri.

ATP synthase imalola mapulotoni kubwerera mu matrix ndipo imagwiritsa ntchito mphamvu zotulutsidwa kuti ilumikize ADP ndi phosphate kupanga ATP. Choncho ndandandawu ndi uwu:

kugwiritsa ntchito oxygen, kenako kupopa mapulotoni, kenako kusiyana kwa mapulotoni, kenako kupanga ATP.

Vuto ndi lakuti mapulotoni angabwerere kudzera m'njira zina. Kubwerera kulikonse komwe sikudutsa mu ATP synthase ndi kutayikira kwa mapulotoni. Kutayikira kumakakamiza ndandandawu kupopanso mapulotoni omwewo kuti kusiyana kwa mphamvu ya magetsi pa nembanemba kusasinthe. Zimenezi zimagwiritsa ntchito oxygen yambiri popanda kupanga ATP yambiri. Kutayikira kukakhala kwakukulu mokwanira, kulumikizana kumasokonekera: kugwiritsa ntchito oxygen kumakwera pamene ATP sikwera kapena imatsika, ndipo mphamvu zowonongekazo zimatuluka monga kutentha.

Mkhalidwe 3, mkhalidwe 4, ndi chiŵerengero cha kuwongolera kupuma kwa maselo

Mawu amene amagwiritsidwa ntchito pofotokoza zimenezi anachokera ku kafukufuku wa mitochondria zopatukana ndi maselo. Mkhalidwe 3 ndi kupuma kwa maselo pamene pali zinthu zopangira mphamvu pamodzi ndi ADP: ATP synthase imachepetsa kusiyana kwa mapulotoni, kusiyana kwa mphamvu ya magetsi pa nembanemba kumatsika, ndandandawu umathamanga kuti ubwezeretse kusiyana kumeneko, ndipo kugwiritsa ntchito oxygen kumakhala kwakukulu chifukwa ATP ikupangidwa. Mkhalidwe 4 ndi kupuma kwa maselo ADP itatha: ATP synthase imasiya kugwira ntchito, kusiyana kwa mapulotoni kumakwera, kusiyana kwakukulu kwa mphamvu ya magetsi pa nembanemba kumalepheretsa kupopa kwina, ndipo kugwiritsa ntchito oxygen kumatsika kufika pa kuchuluka kofunika kubwezeretsa mapulotoni otayikira.

Choncho chiŵerengero cha kuwongolera kupuma kwa maselo, chomwe ndi mkhalidwe 3 wogawidwa ndi mkhalidwe 4, chimasonyeza kulimba kwa kulumikizana m'sampuloyo. Chiŵerengero chachikulu chimatanthauza kuti ADP imawongolera kwambiri kupuma kwa maselo. Chiŵerengero chikamatsika pamene mkhalidwe 4 ukukwera, zimatanthauza kuti kutayikira kukukhala kwakukulu. Kumvetsa zimenezi kumathandiza kufotokoza zotsatira za methylene blue zomwe zili pansipa.

Mfundo imodzi ndi yofunika kukumbukira. Kusiyana kwakukulu kwa mphamvu ya magetsi pa nembanemba kumachedwetsa ndandandawu. Kuchepetsa kusiyana kumeneku kumafulumizitsa ndandandawu. Ndandandawu umasintha malinga ndi mmene kupopa kwakhalira kovuta, osati mwachindunji chifukwa chakuti ATP ikupangidwa kapena ayi.

Pamene zinthu zoyezedwazo zimasintha limodzi

Chitsanzo chomveka bwino kwambiri cha kulumikizana chimachokera ku mitochondria zopatukana ndi maselo a ubongo wa mbewa za mtundu wa guinea pig, zomwe magulu ake a kupuma kwa maselo anatsekedwa. Pa methylene blue ya 100 nanomolar mpaka 1 micromolar, kugwiritsa ntchito oxygen popanda kulimbikitsidwa ndi ADP kunakwera pamene glutamate pamodzi ndi malate, succinate, kapena glycerophosphate zinali zinthu zopangira mphamvu. Koma kupuma kwa maselo kolimbikitsidwa ndi ADP sikunasinthe. Mu mitochondria zomwe complex I kapena complex III inalepheretsedwa ndi poizoni, utotowo unawonjezera pang'ono kupanga ATP, unabwezeretsa kusiyana kwa mphamvu ya magetsi pa nembanemba, ndipo unathandiza kulowetsa calcium. Njira yomwe ofufuzawo anaganiza ndi njira yachidule: utotowo umalandira maelekitironi asanafike pamalo otsekedwa ndi kuwapereka ku cytochrome c, motero kulambalala complex yowonongekayo.

Chitsanzo chachiwiri cha kulumikizana chimagwiritsa ntchito njira ina yosiyana kotheratu yopangira ATP. Mu mitochondria zopatukana ndi maselo a ubongo zomwe ATP synthase inaletsedwa kugwira ntchito, methylene blue inalimbikitsabe kupuma kwa maselo pa chilichonse chopangira mphamvu chomwe chinayesedwa. Koma kupanga ATP kunakwera pa alpha ketoglutarate ndi glutamate zokha, zinthu ziwiri zopangira mphamvu zomwe zimapanga succinyl CoA. Pamene oligomycin inatsekereza ATP synthase, ATP yowonjezerayo inachokera ku kuwonjezera phosphate pa mlingo wa zinthu zopangira mphamvu kudzera mu succinyl CoA ligase m'zungulira wa citric acid, osati ku kuwonjezera phosphate kudzera mu oxidation. Utotowo unabwezeretsanso kusiyana kwa mphamvu ya magetsi pa nembanemba pamene complex I ndi ATP synthase zinaletsedwa kugwira ntchito nthawi imodzimodzi. Pamenepa kugwiritsa ntchito oxygen ndi ATP zinakwera limodzi, koma pokhapokha pamene zinthu zopangira mphamvu zinalola njira yachiwiri yopangira ATP. Pa succinate kapena malate, kupuma kwa maselo kunakwera popanda ATP yowonjezera. Utoto womwewo, chipinda choyesera chomwecho, koma zinthu zopangira mphamvu zosiyana, choncho zotsatira zosiyana.

Pamene zinthu zoyezedwazo zimasiyana

Zitsanzo za kusiyanaku nazonso zafalitsidwa ndipo zimatiphunzitsanso chimodzimodzi. Mu kafukufuku wa 1997 wa mitochondria zopatukana ndi maselo a chiwindi cha makoswe, methylene blue inafulumizitsa kupuma kwa maselo kwa mkhalidwe 4 mu mitochondria zomwe zinkagwiritsa ntchito succinate ndipo zinali ndi kulumikizana kolimba. Zimenezi zinatsitsa chiŵerengero cha kuwongolera kupuma kwa maselo. Kusinthaku kunaonekera kuyambira pa 0.5 micromolar ndipo kunali kwakukulu pa 5 micromolar, kuchuluka koyandikira komwe kumapezeka m'madzi a magazi pambuyo popereka 100 milligram kudzera m'mtsempha nthawi imodzi. Pa 5 micromolar, mitochondria zinatupanso, koma vuto la kulumikizana linaonekera kale pa kuchuluka kocheperapo. Izi zikupereka umboni wakuti kutayikira kunayamba kusanawonongeke kapangidwe, osati chifukwa cha kuwonongekako. Mu mitochondria zomwe kulumikizana kwake kunali kutasokonekera, utotowo unalimbikitsa kupuma kwa maselo m'njira yodalira kuchuluka kwake, koma yomwe inkafika pa malire pomwe kuwonjezera utoto sikunawonjezerenso zotsatira. Kugwiritsa ntchito oxygen kunakwera m'masampulo onse awiri. Kupanga ATP pa oxygen iliyonse yogwiritsidwa ntchito sikunakwere. Ichi ndi chitsanzo chomveka bwino cha kusokoneza kulumikizana pamodzi ndi kunyamula maelekitironi, zonse zikuchitika ndi molekyulu imodzi.

Kusiyana koonekera kwambiri kumachokera ku retina. Mu mbewa zosowa AIF ndi maselo olandira kuwala omwe anapatsidwa rotenone, methylene blue inasunga makulidwe a retina, zizindikiro za maselo olandira kuwala, ndi kapangidwe ka mitochondria. Inachepetsanso chiŵerengero cha NADH poyerekeza ndi NAD ndipo inachepetsa kugwira ntchito kwa njira zoyankha kupsinjika kwa maselo, kuphatikizapo kuyankha mapuloteni osapindika bwino ndi kuwononga mitochondria kudzera mu mitophagy. Inachita zimenezi popanda kukonza kusowa kwa ATP. Kuteteza popanda kubwezeretsa mphamvu kumatanthauza kuti phindulo linachokera ku kulinganiza kwa redox ndi kusungidwa kwa kapangidwe ndi kugwira ntchito kwa mitochondria, osati ku ATP yowonjezera. Aliyense amene angaganize kuti kupulumuka kwa minofuyo kunatanthauza kubwezeretsedwa kwa kupanga mphamvu angamvetse molakwika kotheratu mayeserowo.

Kafukufuku wa mitochondria za ubongo akuwonjezera mbali ya kuipa ku zotsatira zomwezo. Kuchuluka kochepa komwe kunathandiza njira zopangira ndi kugwiritsa ntchito mphamvu kunawonjezeranso kupanga hydrogen peroxide m'mikhalidwe yonse yoyesedwa ndipo kunachedwetsa kuchotsedwa kwake. Izi zinayesedwa ndi njira ya Amplex yokonzedwa kuti ipereke miyezo yolondola, osati ndi utoto wosazindikira chinthu chimodzi chokha. ATP yambiri ndi chinthu chowonjezera oxidation chochuluka zinabwera limodzi.

Mndandanda wothandiza powerenga

Mafunso anayi amasiyanitsa zotsatira zomwe kulumikizana kunasungidwa ndi zomwe kulumikizana kunasokonekera.

Choyamba, kodi chinayezedwa ndi chiyani kwenikweni? Kugwiritsa ntchito oxygen kokha sikungasonyeze ATP. Kupanga ATP, kusiyana kwa mphamvu ya magetsi pa nembanemba, ndi chiŵerengero cha kuwongolera kupuma kwa maselo, chilichonse chimapereka mfundo imodzi yomwe elekitirodi ya oxygen singasonyeze. Buku lotsogolera powerenga zonena za kafukufuku wa methylene blue limafotokoza mwatsatanetsatane kufunika koyang'anira zomwe zinayezedwadi.

Chachiwiri, kodi mitochondria zinapatsidwa chiyani chopangira mphamvu? Zotsatira za succinyl CoA zikusonyeza kuti kusankha zinthu zopangira mphamvu kungasankhe ngati kupuma kwa maselo kowonjezera kungapangitse ATP yowonjezera kapena ayi.

Chachitatu, kodi anagwiritsa ntchito kuchuluka kotani? Methylene blue ya nanomolar mpaka micromolar yochepa mu mitochondria za ubongo inathandiza pang'ono njira za mphamvu koma inawonjezeranso zinthu zoyambitsa oxidation; theka la micromolar ndi kupitirira apo mu mitochondria za chiwindi zinafooketsa kulumikizana; 5 micromolar inawonjezeranso kutupa. Kuchuluka kwake ndi mbali ya mmene imagwirira ntchito, osati tsatanetsatane wamba.

Chachinayi, kodi zotsatira zinachokera ku chitsanzo choyesera chotani? Mitochondria zopatukana ndi maselo zimasonyeza mmene njira zake zimalumikizirana, koma maselo ndi minofu yosapatukana zimawonjezera kunyamula zinthu, kusanduka kwa methylene blue kukhala mtundu wopanda mtundu kudzera mu reduction, ndi njira zina zolandira maelekitironi zomwe zimapikisana. Kafukufuku wa kuchuluka koperekedwa m'mayesero a labotale, kuphatikizapo mmene kuchuluka ndi ndondomeko ya mayesero zimasinthira zotsatira za methylene blue, ndiwo mlatho pakati pa manambala a m'chipinda choyesera ndi zonena zilizonse zokhudza munthu.

Kugwiritsa ntchito oxygen kumasonyeza kuyenda kwa maelekitironi. ATP imasonyeza kuchuluka kwa mphamvu za kuyenda kumeneko zomwe zasungidwa. Methylene blue ingasinthe chilichonse mwa ziwirizi, ndipo mayesero amene ali pamwambawa akusonyeza mitundu yonse inayi ya zotsatira: zonse ziwiri zimakwera, kupuma kwa maselo kumakwera koma ATP imakwera kokha pamene zinthu zopangira mphamvu zilola, kupuma kwa maselo kumakwera pamene kulumikizana kukuchepa, ndipo minofu imasungidwa pamene ATP sikusintha. Nambala ya pa elekitirodi ya oxygen ndi poyambira kumasulira zotsatira, osati pomalizira.