Ungahlala kanjani umusha kuze kube phakade

Minyaka yonke imboni yobuhle ingenisa izigidigidi zamaRandi ithengisa izinto zokuthambisa, amaserum, nezithako zomlingo ukuze kuvinjelwe ukuguga kubantu abasha ngokuxakayo. Yibhizinisi eliphelele; kuyohlale kukhona abantu abesabayo inqubo yokuguga, futhi kuyohlale kukhona ukuqhubeka okungenakugwemeka kwesikhathi okwehlisa kancane kancane imizimba yabo. Ngokwezinga elithile, umphakathi wethu uyohlale uthanda abasha nabahle, udala ugqozi oluhle kakhulu lokusebenzisa imali kuzixazululo zobuhle. Kodwa-ke, wonke la makhambi "afakazelwe ngokomtholampilo" ekugcineni awenzi lutho ukulwa nokuguga. Impela, le mikhiqizo igcwalisa imibimbi futhi ithuthukise ukubukeka (ngiyakwazi ukuzwa izikhangiso manje - "Iqina! Iqini! OMNCANE!"). Kodwa umzimba uyaqhubeka nokuguga. Mhlawumbe isayensi iyishaye kakhulu imboni yobuhle ngale mali- ukwenza inkinga ngokudalula indlela yeqiniso yokumisa ukuguga.

Kungani siguga

Muva nje, iNational Institute of Health (NIH) ngokubambisana noRodrigo Calado, uprofesa eNyuvesi yaseSao Paulo Ribeirao Preto Medical School, baphothule ukuhlolwa komtholampilo ngokwelashwa kwezidakamizwa okuthiwa i-Danazol. I-Danazol ilwa nembangela yebhayoloji ewumsuka yokuguga: ukuwohloka kwe-telomere. Nakuba lokhu kwelashwa kwenzelwe abantu abahlushwa ukuguga ngaphambi kwesikhathi kanye nesifo esiwohlozayo esibangelwa ukuntuleka kwe-telomerase, i-Danazol ingashintshwa njengomuthi wokulwa nokuguga.

I-telomeres, isakhiwo se-DNA-protein, ithathwa njengesihluthulelo sokuguga ngenxa yobudlelwane bawo nama-chromosome. Wonke umsebenzi womzimba owodwa nenqubo ibhalwe ngekhodi kumapulani e-chromosomal. Ama-chromosome engqamuzana ngalinye emzimbeni abalulekile emsebenzini walelo ngqamuzana. Nokho, la ma-chromosome asetshenziswa njalo ngenxa yokuthi amaphutha enziwa phakathi nenqubo yokuphindaphinda kwe-DNA nangenxa yokuthi kuvamile ukuba ama-nucleotide wonakale ngokuhamba kwesikhathi. Ukuze kuvikelwe ulwazi lofuzo lwe-chromosome, i-telomere itholakala ekugcineni kwe-chromosome. I-telomere iyalimala futhi yehlise isithunzi esikhundleni sezakhi zofuzo ingqamuzana eliyidinga kakhulu. Lawa ma-telomere asiza ukugcina ukusebenza kwengqamuzana. 

Ukugcina Intsha yethu

Ama-telomere kubantu abadala abanempilo amapheya ayisisekelo angama-7000-9000 ubude, enza umgoqo oqinile omelene nomonakalo we-DNA. Uma ama-telomere emude, kulapho i-chromosome ikwazi ukumelana nalowo monakalo. Ubude bama-telomere bomuntu buthintwa ukushayisana kwezici ezihlukahlukene ezihlanganisa isisindo somzimba, indawo ezungezile, nesimo somnotho. Ukudla okunempilo, ukuvivinya umzimba okuvamile, namazinga okucindezeleka amaphakathi kunciphisa ukufinyela kwe-telomere kakhulu. Ngakolunye uhlangothi, ukukhuluphala ngokweqile, ukudla okungenampilo noma okungajwayelekile, amazinga aphezulu okucindezeleka nemikhuba efana nokubhema kunomthelela omubi kakhulu kuma-telomere omzimba. Njengoba ama-telomere ewohloka, ama-chromosome asengozini enkulu. Ngenxa yalokho, njengoba ama-telomere eba mfushane, amathuba okuba nesifo senhliziyo, ukwehluleka kwenhliziyo, isifo sikashukela, umdlavuza kanye nesifo samathambo ayanda, konke okuvamile lapho umuntu esegugile. 

I-enzyme telomerase ingandisa ubude be-telomeres yomzimba. Le enzyme ivame kakhulu kumaseli ngesikhathi sokukhula kwangaphambi kwesikhathi futhi itholakala kuphela emazingeni aphansi kumaseli amadala emzimbeni. Kodwa-ke, phakathi nocwaningo lwabo i-NIH ne-Calado bathola ukuthi i-androgens, isandulela sama-steroid kumahomoni omuntu, ezinhlelweni ezingezona ezomuntu zandisa ukusebenza kwe-telomerase. Ukuhlolwa komtholampilo kwenziwa ukuze kubonakale ukuthi umphumela ofanayo uzokwenzeka yini kubantu. Imiphumela yabonisa ukuthi, ngenxa yokuthi ama-androgens aguquka ngokushesha abe ama-estrogens emzimbeni womuntu, kuphumelela kakhulu ukusebenzisa i-hormone yesilisa yokwenziwa i-Danazol esikhundleni salokho.   

Kubantu abadala abanempilo, ama-telomere afinyezwa ngamapheya ayisisekelo angama-25-28 ngonyaka; uguquko oluncane, olungelutho oluvumela impilo ende. Iziguli ezingama-27 ocwaningweni lomtholampilo zazinezinguquko zofuzo ze-telomerase futhi, ngenxa yalokho, zazilahlekelwa kusuka kumapheya ayisisekelo ayi-100 kuye kwangama-300 ngonyaka ku-telomere ngayinye. Ucwaningo, olwenziwa eminyakeni emibili yokwelashwa, lubonise ukuthi ubude be-telomere yeziguli bukhuphuke ngamapheya angama-386 ngonyaka ngokwesilinganiso.