Amafutha Brown kubantu: incazelo imisebenzi kanye nezici

Kuyini amafutha brown? Iyini imisebenzi ke wenza? On zale mibuzo kanye neminye sizobe ngayo kulesi sihloko. Emzimbeni womuntu kukhona izinhlobo ezimbili okunamafutha izinto: brown (Bat - ngenxa evutha amafutha inikeza thermogenesis futhi kudala ukushisa) nomhlophe (the Wat - eyenzelwe isitoreji amandla). Abantu abakhuluphele bathambekele amafutha elinsundu kancane, kanye emhlophe - ngaphezulu.

umsebenzi

amafutha Brown evumela umzimba ukuze kulondolozwe izinga lokushisa njalo. Le ndlela yokwenza libizwa thermogenesis. Zimbili izinhlobo thermogenesis: i contractile (babeqhaqhazela ngenxa yezihlambi zemvula), lapho isizukulwane ukushisa kungenxa ukunciphisa imisipha lwamathambo (mkhuba esithile - abandayo imisipha eliqhaqhazelayo), futhi beqhaqhazela (umsebenzi amafutha brown).

Ukuze ulwe ngempumelelo okunye ukugula komuntu lokushisa lomzimba inyuka wedwa. Uma othile uhlushwa imfiva, yena kabusha ngokushesha ohlelweni thermoregulatory inikwe amandla futhi iqala ukuba usebenze ezingeni eliphakeme. Yingakho lokushisa lomzimba akudingekile ngehlisa 38.5 degrees.

nokwakheka

Okokuqala amafutha brown etholakala ezilwaneni. Labo izilwane awela basebusika ebusika ukuthi, yalolu ketshezi is best athuthukile, njengoba kule nkathi umzimba kubambezela. Ngenxa yalokhu-ke akunakwenzeka ukuba silondoloze lokushisa lomzimba imisipha Kufinyeta.

Lokunye lokubaluleke kakhulu amafutha brown nokuvuka entwasahlobo izilwane: ngabo elakhiwe ukushisa umzimba lokushisa kakhulu anda, ngenxa lapho isilwane evuka.

abanikazi

Izimo zethu zihluke kakhulu muva yabe seyaziwa ukuthi amafutha brown itholakala kuphela izingane. Kuyabasiza ukujwayela indawo entsha emva kokuzalwa. Ngo izinsana yalolu ketshezi itholakala endaweni izinso, intamo kanye ngemuva engenhla, emahlombe, futhi mayelana 5% esisindo.

Futhi emzimbeni ngezinye izikhathi izingane amafutha brown ixubene emhlophe. Izingane izidakamizwa brown kubaluleke kakhulu, njengoba sibavikela hypothermia, ngenxa okuyinto ezizalwa ngaphambi kwesikhathi ngokuvamile ziyafa. Ngenxa yalesi ingxenye ezinsaneni kancane sensitive amakhaza kunabantu abadala.

Amaseli we brown amafutha has a izinga eyingqayizivele - kukhona lenqwaba mitochondria (organelles anomthelela isitoreji amandla). Siyabonga kubo, bona, empeleni babe umbala yabo. Mitochondria aqukethe ethize amaprotheni UCP1, okuyinto, ngokudlula isinyathelo ATP zamagama kweso iguqula fatty acid ku ukushisa.

Triglyceride (lipids) ekhona Ukwakheka amafutha izithombe kusuka okungase oluqanjwe ukushisa (ATP). Lapho umntwana udinga amandla amaningi (isibonelo, ukuze ifudumale), amafutha ibhekane lipolysis. Ngenxa yalokho, kukhona acid onamafutha UCP1 kumaseli fat brown siguqule ukushisa. Ngenxa yalokho, ukwehla fat umzimba izinqolobane. Okokuqala wachitha triglyceride ngoqobo ansundu kakhulu, njalo lapho lipid izinqolobane uqale kuyanyamalala, kuqine esimhlophe ezinenzondo.

Ngenxa yalokho, umzimba kwehlisa isisindo sayo. Nokho, i-nekusebenta inqubo ingane, ozalwa, kufanele udle kahle (ukwenza kusebenze lipolysis kudingeka amandla) aphefumule evamile (i aguqulayo fatty acid adinga i-oksijini).

Ngeshwa, omdala, leli washi kancane kancane buthakathaka. Ngemva kwamasonto ambalwa, esezele ukuphahlaza (ku hypothermia ukuphendula) singena esikhundleni saleTitatimende isenzo into ensundu, izingane ikakhulukazi uma sigqoke ngokufudumele futhi uwagcine ekamelweni hot.

abantu abadala

Namuhla, lwathola ukuthi amafutha nsundu abadala iyatholakala. Kwaphela isikhathi eside kwakucatshangwa ukuthi yalolu ketshezi ubuqotho ekupheleni konyaka wokuqala wokuphila. Nokho, ngo-2008, izazi sinqume ukuthi brown izicubu adipose is hhayi kuphela uhlala emzimbeni abadala (kwaziwa ngo-1908), kodwa ivuswe ngu abandayo.

Lokhu kwatholakala nge imifanekiso yobuchopho umzimba esebenzayo ezicutshini entsha. Sasebenzisa positron ekushayweni-ngekhompyutha tomography kwezinto, eyabonisa ukuthi emzimbeni komuntu omdala imayelana 20-30 amagremu (okuncane) obusebenzayo amafutha ensundu, ikakhulukazi endaweni supraclavicular.

Kuyaziwa ukuthi PET-CT kuthola umzimba umsebenzi ihlule. Physiologist Wouter van Marken Lihtenbelt libike ukuthi iqembu labantu abasha (abantu 24) anikezwa umthamo eqondile glucose enemisebe. Lokhu kwakwenziwa ukuze ukwazi ukuthola amafutha brown ngaphezulu asebenzayo ngedivayisi ethile.

Ngemva kwalokho, abantu abahlanganyela kulolu cwaningo sezishiye egumbini lapho izinga lokushisa akazange idlule degrees 16. I-CT scan wabonisa ukuthi ngaphansi kwesikhumba esifubeni, entanyeni belly fat kuyinto 23 abantu "ewusizo" indwangu esebenza, ukufudumala abantu egumbini abandayo.

Physiologist, wathi ochwepheshe zamangala lapho zibona abantu ukuthi abantu kangaka futhi eziningi kangaka. Lapho uhlolwa ngaso ekamelweni lokushisa abahlanganyeli ezintathu, imfuyo brown ayitholakalanga. Izazi zikholelwa ukuthi le ndwangu ingabe usekhona, kodwa umane saphela ukusebenza kwawo.

ukusebenza

Ngakho wazi lapho umuntu amafutha ensundu. Akukhona ezingaphezu kuka 1-2% esisindo. Kodwa nokho, uma nonozwela isimiso sezinzwa kuvusa kwezicubu ku ezincelisayo supercooled ngubani zijwayele abandayo, it kwandisa ukukhiqizwa yayo ukushisa. Amandla elakhiwe kungaba ngaleyo ndlela uthole okwengeziwe ingxenye eyodwa kwezintathu ukushisa wadala emzimbeni. Lapho amafutha brown icushiwe, echitha kuze kube Watts 300 (abanye ucingo 400 Watts) kilogram yomuntu omdala ngayinye.

Kuyaziwa ukuthi umuntu isisindo isilinganiso ngesikhathi eshisa ingxenye esele yombhalo mayelana 1 kW amandla. Ukwenza amafutha ensundu, ungakwazi amanga embhedeni futhi bachithe amandla izikhathi ezingamashumi amabili kunakuqala.

esivuthayo fat

Yini amanoni brown? It kudambisa amafutha. Uma yenziwe yasebenza, acid okunamafutha kusuka elimhlophe adipose izicubu zidluliselwa ku-brown. Ingqikithi omhlophe zibekwe capsule kanye nezindlala yezitho zangaphakathi, ngaphansi kwesikhumba. Brown, esikhundleni isitoreji amandla, evutha ke inqwaba. Ngenxa yalokho, ukushisa ikhishwe. Le nqubo ibizwa ngokuthi thermogenesis oqala umsebenzi walo ngenxa ukudla ngokweqile ukusetshenziswa.

okutholakele

White futhi nsundu amafutha - abayikho izinto ezimbili ezahlukene. Oxidative umthamo izidakamizwa elinsundu izikhathi 20 obukhulu kunobukaJohane esimhlophe. Brown izicubu thermogenesis izenzo Thermogenin amaprotheni egqugquzela kwezimila uncoupling futhi phosphorylation oxidative.

Ngakho, sathola ukuthi lo amafutha ensundu. Kanjani ukwandisa inani emzimbeni womuntu ukulwa ngempumelelo ukukhuluphala ngokweqile? Ukuze uxazulule le nkinga, abacwaningi isetshenziswe izidakamizwa kuphela, kodwa futhi kusho kuhlinzwa: usebenzisa liposuction kuthiwa evamile amafutha ezimhlophe akhiphe, uguqule bayifaka ansundu kakhulu, njalo futhi ezifakelwa kumuntu.

Kwakucatshangwa ukuthi ukuze ulahlekelwe isisindo, kufanele noma ukwandisa umsebenzi ketshezi brown ashisa evamile, noma ukwandisa isibalo saso, noma enze kokubili kuqala, futhi eyesibili.

Isifo sikashukela Ochwepheshe Association of-United States zikholelwa ukuthi amafutha brown unamalungiselelo kubaluleke kakhulu iziguli isifo sikashukela nokukhuluphala ngokweqile. It is eyaziwa ukuthi umsebenzi ephelele amafutha womuntu onsundu is bebengaphuzile, kanye nenani layo encishisiwe. Ngakho-ke, esikhathini esizayo esiseduze kungenzeka ukuvela umuthi omusha nezinye izindlela wayenemfuyo futhi ukusebenza kwawo izinto "ewusizo" kwabadala.