Whakamātautau Ames mo N-Nitrosamines: Te Aromatawai i te Mutagenicity

Whakataki ki te Whakamatau Ames

Ko te whakamatautau Ames, e mohiotia ana ko Bacterial Reverse Mutation Test he mea whakamahia whanui mo te whakamatautau koiora e aromatawai ana i te kaha mutagenic o nga pūhui matū, tae atu ki te N-Nitrosamines. I hangaia e Dr. Bruce Ames i te tekau tau atu i 1970, ka whakamahi tenei whakamatautau i nga riaka motuhake o te huakita Salmonella typhimurium e kawe ana i nga huringa o nga ira e uru ana ki te whakahiato histidine. Ka whakatauhia e te whakamatautau mena ka taea e tetahi matū te whakarereke i te DNA huakita, e tohu ana mo te mate mate pukupuku o te tangata.

Tikanga o te Whakamatau Ames mo N-Nitrosamines

E mohiotia ana a N-Nitrosamines mo o ratou taonga whakaraerae me te mate pukupuku, na te mea ka taea e ratou te whakararu i te kino o te DNA na roto i te alkylation me te ahotea oxidative. He tino whai hua te whakamatautau Ames ki te kite i o raatau paanga mutagenic, i te mea he maha nga N-Nitrosamines e hiahia ana ki te whakahohenga pūkoro ma te huringa enzymatic ki te hanga i nga takawaenga electrophilic tino tauhohe e kaha ana ki te taunekeneke me te DNA. Ko tenei whakahohenga ka puta i roto i te ate na roto i nga enzymes cytochrome P450. Hei whakahoki ano i tenei huringa metabolic in vitro, he maha nga wa e whakahaerehia ana te whakamatautau me te kore o te whakahoahoatanga o te tinana ma te whakamahi i te ranunga S9, he whakarite i te whanariki ate i ahu mai i nga kiore, e whakatauira ana i te paopaotanga maminga me te whakarei ake i te kitenga o te mahi mutagenic.

Tikanga mo te Whakamatau Ames

Ko te tikanga paerewa o te whakamatautau Ames e whai ake nei:

1. 1. Te Whakaritenga o nga Ranga Whakamatau: Ka whakamahia nga riaka Salmonella typhimurium me nga huringa o mua i roto i nga ira whakahiato histidine. Kare e taea e enei riaka te tipu me te kore he puna histidine o waho ki te kore e hoki mai te mahi a te huringa whakamuri.
2. 2. Te Maranga ki te N-Nitrosamines: Ka konatunatua te ahurea huakita ki te puhui whakamatautau (N-Nitrosamine) i runga i te pereti agar iti kei roto he iti o te histidine.
3. 3. Whakahohenga Metabolic (S9 Mix Addition): Hei whakaatu mo te hurihanga o te tinana o te tangata, ko etahi tauira whakamatautau ko te hautanga S9, he tangohanga enzymatic mai i nga microsomes ate kiore.
4. 4. Incubation and Growth: Ka whakakororia nga papa ki te 37°C mo te 48 haora, ka taea te tipu o nga koroni huakita mena ka puta he rerekee hei whakahoki i te whakahiato histidine.
5. 5. Te Tatau me te Tatautanga o te Koroni: Ka tatauhia te maha o nga koroni revertant (huakita i hoki mai te kaha ki te whakaputa histidine) ka whakatauritea ki nga pereti whakahaere.
6. Te whakamaoritanga o nga Hua

• Whakamātautau Ames Pai: Ko te pikinga nui o nga koroni ka huri ki te whakataurite ki te mana whakahaere e kii ana ko te puhui e whakaohooho ana i nga huringa, e kii ana i nga ahuatanga mutagenic me te mate pukupuku.
• Whakamātautau Ames kino: Ki te kore e kitea he pikinga nui, karekau pea te pūhui i raro i nga tikanga whakamatautau.
• Pota-Whakautu Hononga: Ko te nui ake o nga pota ka piki ake te tere o te whakarereketanga e whakakaha ana i nga taunakitanga o te rerekeetanga.

Whakamutunga

Ko te whakamatautau Ames he tikanga tere me te utu-whai hua mo te aromatawai i te rereketanga o te N-Nitrosamines. I runga i o raatau hononga ki te mate pukupuku, ko te tautuhi i o raatau ahuatanga mutagenic ma tenei whakamatautau he mea nui mo te whakahaere ture me te aromatawai morearea. Ko tenei whakamatautau ka noho tonu hei kohatu kokonga mo te tirotiro paitini me te aromatawai haumaru matū.

Kupumatua: N-Nitrosamines, NDSRIs, OECD 471, Whakanuia te whakamatautau Ames, Hamster ate S9, Cytochrome P450 enzymes, Mutation Test