Te kikorangi metilīni me te kite: ngā kitenga o te rangahau retina me ōna herenga

Ka kitea e tētahi kaipānui he rangahau i tiakina ai te retina e te kikorangi metilīni, kātahi ka puta te pātai e tika ana: me tuku rānei ki roto i te kanohi? Kāore te rangahau mō te kikorangi metilīni me te kite e whakautu i taua pātai, nā te mea kāore tētahi o ngā rangahau matua i whakamātau i taua whakamahinga. I tētahi, i werohia te waikano ki roto i te wai kōataata o ngā kanohi kiore me tētahi tāoke. I tētahi atu, i tāpirihia ki te wai whakatipu e karapoti ana i ngā pūtau kua wehea ki roto i tētahi rīhi. I tētahi atu, i tukuna ki te wai inu o ngā kiore irakē. E hāngai ana ia kitenga ki tōna ake ara tuku me tōna ake tauira rangahau.

Ka tirohia e tēnei tuhinga ngā rangahau e toru i mua i te whakamātautau haumanu, ngā momo pūtau retina e rua, me te rohe i waenga i te tiaki pūtau i te taiwhanga me te maimoatanga haumanu mō te kanohi. He ōrite te ia o ngā kitenga: ka taea e te kikorangi metilīni te whakarerekē i te ahotea o ngā mitokōria i roto i ngā pūtau retina i raro i ngā āhuatanga whakahaere, engari kāore taua kitenga e whakamana i te tuku wairewa hokohoko ki te kanohi.

E rua ngā momo pūtau, e rua ngā mate rerekē

He paparanga tō te retina, ā, he mea nui ko tēhea paparanga e tirohia ana. Ka pā tuatahi te mārama ki ngā pūtau tairongo ki te mārama i te retina o waho. Ka whakawhitihia ā rātou tohu mā ngā pūtau io takawaenga ki ngā pūtau ganglion retina i te retina o roto, ā, ka puta atu ngā akahono o aua pūtau mā te io whatu. E whakaingoatia ana ngā paparanga i raro nei, i runga i tō rātou raupapa.

Ko ngā pūtau ganglion retina ngā pūtau ka pāngia e te papahewa me te mate o te io whatu. Ina kōrerotia te kikorangi metilīni me te papahewa i ngā rapunga, ko tēnei paparanga o roto me ōna akahono te tikanga. Ko ngā pūtau tairongo ki te mārama ngā pūtau ka pāngia e te hekenga o te retina o waho. Ko ēnei ngā pūtau e nui rawa ana te hiahia pūngao i te retina, ā, ka mahi tata ki te mōrahi o tō rātou kaha whakaputa pūngao mā te hāora. Nā reira, he iti noa te kaha tāpiri e toe ana ina kore e mahi te matatini I o ngā mitokōria. Kāore tētahi kitenga mō tētahi momo pūtau e pā noa ki tētahi atu momo, ā, ka noho wehe ēnei momo i ngā rangahau e toru i raro nei. Ka whakamāramatia te pūkenga whānui o te wehe i ngā tauira rangahau i ngā whakatau i roto i te pānui rangahau mō te kikorangi metilīni.

Ngā pūtau ganglion i roto i te kanohi o te kiore ora

I te rangahau tuatahi o ēnei rangahau e toru, i waihangatia e ngā kairangahau he tauira o te mate io whatu mā te wero moroiti i te rotenone ki roto i te wai kōataata o tētahi kanohi kiore, ā, ko tērā atu kanohi te whakataurite whakahaere i whiwhi i te wai kawe anake. Ka aukati te rotenone i te matatini I o ngā mitokōria, arā, te tomokanga e whakawhiti whakamua ana i ngā irahiko mai i te NADH. Ko te hapa mahi o te matatini I hoki te āhuatanga e hono ana i tēnei tauira ki te mate io whatu tuku iho o Leber, he mate o ngā pūtau ganglion me te io whatu.

Rua tekau mā whā hāora i muri mai, he angiangi ake te paparanga pūtau ganglion i ngā kanohi i whiwhi rotenone, ā, he iti ake ngā pūtau i ērā o ngā kanohi whakataurite. Ina werohia ngātahitia te kikorangi metilīni me te rotenone, i āraia taua kino i runga i te nui o te horopeta. Nā te horopeta nui rawa i whakamātauria (0.07 mg/kg, he iti rawa iho i te LD50 mō te kiore) i tiaki te mātotoru o te paparanga me te maha o ngā pūtau. I ngā whakamātautau whakarara i ngā kiko roro kua hurihia kia ōrite te ranunga, e rua ngā pānga i kitea: i whakahokia whakamuri e te kikorangi metilīni te ahotea hāoratanga nā te rotenone, me te hekenga o te whakamahinga hāora. I whakatakotoria e ngā kaituhi he tikanga paitini nā te whakaongaonga nui rawa: ka whara ngā pūtau amacrine whakahaere i te rotenone, ka kaha rawa te tuku tohu a ngā pūtau ganglion, ā, ka haukotia te kino ka hua ake e te mahi ārai hāoratanga. Ka whakamāramatia te matū e whakaarotia ana kei muri i taua tiakitanga i roto i ngā tikanga mahi a te kikorangi metilīni i ngā mitokōria.

E toru ngā herenga o tēnei kitenga. I werohia ngātahitia te waikano me te tāoke ki roto tonu i te kanohi. He tikanga tuku tēnei, ehara i te hōtaka maimoatanga. He 24 hāora te wā mātakitaki. Ā, i piki ngā inenga o te cytochrome oxidase i ngā rōpū e rua i whara. Ki ngā kaituhi, he tohu tēnei o te mahi kaha rawa, kāore he taunakitanga kua whakahokia te mahi whakaputa pūngao mā te hāora i roto i te retina ora.

Ngā pūtau ganglion kua wehea ki roto i tētahi rīhi

I tangohia katoatia te kanohi i te rangahau tuarua. I wehea e ngā kairangahau ngā pūtau ganglion retina taketake mai i ngā kiore nui taitamariki, ka tukuna ki te rotenone, ki te staurosporine e whakaoho ana i te apoptosis, ki te āhuatanga hāora iti mō te 72 hāora rānei, kātahi ka ine i te oranga mā tētahi waikano e tohu ana i ngā pūtau ora me ngā pūtau mate. I te 1 me te 10 micromolar o te kikorangi metilīni i roto i te wai whakatipu, i pai ake te oranga i raro i ia momo whakararu, tata ki te 1.5 ki te 1.9 whakareatanga, e ai ki te āhuatanga. I whakaatu tētahi whakamātautau hoa i tiakina e te kikorangi metilīni te mahi a te cytochrome c oxidase i te wā i tukuna ai te hauwai perōkai hei whakararu.

He rangahau mahi matū tēnei i ngā pūtau kua wehea. I tae te pūhui ki ngā pūtau mā te tūringiringi i roto i te wai whakatipu, i tētahi kukūtanga kua tautuhia. Kāore he taupoki mārama o te kanohi, he kiriata roimata, he arotahi, he wai kōataata, he rere toto, he pūnaha ārai mate rānei i te ara. Ko taua māmātanga te kaupapa o te tauira: e whakaatu ana ka taea te tiaki i ngā pūtau ganglion ake ina tae te pūhui ki a rātou. Kāore e kōrero ana mēnā ka tukuna e tētahi pata i runga i te mata o te taupoki mārama he kukūtanga kua tautuhia ki te retina o roto. I karohia ngā kukūtanga i runga ake i te 10 micromolar nā te paitini ki aua pūtau anō. He whakamaharatanga tēnei ka taea e te whakapiki horopeta i roto i tētahi rīhi te whakaputa pānga pai, pānga kino hoki.

Ngā pūtau tairongo ki te mārama i ngā kiore irakē me tētahi rārangi pūtau

E pā ana te rangahau tuatoru ki te retina o waho. I whakamahia e ngā kairangahau ngā kiore Harlequin, he ngoikore tō rātou pūmua whakaoho apoptosis, e kore ai e oti te whakahiato o te matatini I, ā, i tirohia te hanganga o ngā pūtau tairongo ki te mārama, ngā tohu o ngā wāhanga o waho, me te noho pai o ngā mitokōria i te 11 marama o te pakeke. I tukuna te kikorangi metilīni ki te tinana katoa mā te wai inu i muri i te whakamutu whāngai ū, tata ki te 10 mg/kg ia rā. I ngā kiore irakē i whiwhi i te matū, he nui ake te mātotoru retina i mau tonu, he nui ake ngā tohu rhodopsin me te opsin, ā, he pai ake te hanganga mitokōria i ērā o ngā kiore irakē kāore i whiwhi i te matū.

I whakamahia ngā pūtau 661W i te mahi pūtau hoa. He rārangi pūtau ēnei e rite ana ki ngā pūtau tairongo ki te mārama o te kiore, kua whakarerekētia kia kaha tonu te whakatipu. I tukuna ēnei ki te rotenone, me te kikorangi metilīni, me te kore rānei, mō te 24 hāora. I pai ake te oranga i te 30 micromolar, ā, nā ngā kukūtanga iti ake i whakahoki te ōwehenga NADH ki te NAD+ ki te taumata noa, i whakaiti hoki i te ahotea hāoratanga. Ko te kōrero tino kitea ko te mea kāore i mahia e te kikorangi metilīni: kāore i whakahokia te ATP. I whai te tiakitanga i te whakangāwari o te ahotea hāora-whakaheke me te whakaiti i ngā ara urupare ahotea, tae atu ki te urupare mitokōria ki ngā pūmua kāore anō kia kōpaki tika me ngā tohu o te whakakore mitokōria. Kāore i whai i te whakahokinga o te tuku pūngao.

He mea nui taua wehenga mō ngā kerēme mō te kikorangi metilīni me te retina. Ka taea e tētahi pūhui te pupuri kia ora tētahi pūtau tairongo ki te mārama kei raro i te ahotea, me te kore e whakatika i tōna korenga pūngao. Nā tēnei ka whāiti te whakamāramatanga o tētahi whakamahinga haumanu ki te ahotea hāora-whakaheke, kaua ki te whakahou whānui.

Ngā rangahau e toru, taha ki te taha

Ka tapaina ia rangahau i te whakataurite i raro nei ki tōna tauira me tōna ara tuku, nā te mea mā aua tīwae e rua e whakatau he aha ka taea te tautoko e te kitenga.

He rangahau i mua i te whakamātautau haumanu ngā rārangi katoa. Kāore tētahi i whakauru tūroro, i ine i te kite, i whakamātau rānei i tētahi whakaritenga matū mō te kanohi.

He aha tēnei kāore ai i te maimoatanga mō te papahewa

Ka whakaheke te tiaki papahewa i te pēhanga o roto o te kanohi. He mahi kē tā te tiaki io: he pupuri kia ora ngā pūtau ganglion me ō rātou akahono i raro i te ahotea. E hāngai ana ngā rangahau o runga ki te mahi tuarua, ehara ki te mahi tuatahi. Kāore tētahi i whakaheke i te pēhanga, ā, kāore tētahi i whakataurite i te kikorangi metilīni ki tētahi maimoatanga whakaheke pēhanga. Nā reira, he pātai motuhake tonu ngā tikanga kua whakatūria mō te papahewa me te whakahaere pēhanga i te tiaki io mā te hāora-whakaheke. Nā reira hoki, kāore e taea te pānui i tētahi kitenga oranga pūtau hei tohu kua tiakina te kite.

Ka whakapakari ngā rerekētanga ara tuku i taua kōrero. Mā te wero ngātahi ki roto i te wai kōataata ka tukuna he rahinga e mōhiotia ana ki te taha o te retina i te wā tonu o te wharanga. Mā te tuku horopeta i te wai inu ka pā te matū ki te kararehe katoa mō ngā marama, me te kore e mōhiotia te kukūtanga i te retina. Mā te wai whakatipu ka pā tika te matū ki ngā pūtau karekau he kiko e karapoti ana. Kāore tētahi o ēnei e matapae he aha te hautanga o tētahi horopeta ka tukuna ki te mata o te kanohi ka whakawhiti i te taupoki mārama, ka kore e tangohia e ngā roimata, ka haere mā te arotahi me te wai kōataata, ā, ka tae ki tētahi o ngā paparanga retina i tētahi kukūtanga whai hua. Ko taua raruraru tuku tētahi wāhanga o te pātai whānui mō ngā ara tuku me te tohatoha o te kikorangi metilīni, e hiahiatia ai he inenga kukūtanga motuhake mō ia ara.

He tauārai tuarua tō ngā rerekētanga kiko. Kāore te waikano kua tae ki mua o te kanohi i tae atu ki muri, ā, tērā pea ka whara tētahi paparanga i te kukūtanga e āwhina ana i tētahi atu. Kāore ngā wairewa hokohoko e hangaia, e whakahoromatahia, e whakatikahia kia pūmau te pH, e tāpirihia rānei ki ngā matū tiaki kia rite ki ngā whakaritenga mō te kanohi. He mea nui katoa te parakore, te pH, te osmolality, me ngā matū āpiti mō te pānga ki te taupoki mārama me roto o te kanohi. Kāore tētahi o ēnei kitenga retina e whakamana i te tuku i aua wairewa ki roto, ki runga rānei i te kanohi. Ko ngā pātai mō ngā paerewa whakarite matū e hāngai ana ki te haumaru me te whakahaere i te kikorangi metilīni.

Te wāhi ka mutu te taunakitanga

Ina pānuihia ngātahitia, ka tautoko ngā pepa e toru i tētahi kerēme whāiti: i raro i ngā āhuatanga whakahaere, ka taea e te kikorangi metilīni te whakangāwari i te ahotea hāora-whakaheke o ngā mitokōria i roto i ngā pūtau io retina, me te tiaki i tō rātou hanganga. Ka mutu te kerēme i te wāhi ka mutu aua āhuatanga. Ko ngā tauira tāoke me ngā tauira ā-ira o te matatini I ehara i te papahewa, i ngā putunga drusen, i te mate nā te mate huka rānei. Ko ngā wā poto me ngā inenga whakamutunga o te hanganga ehara i te kite e mau tonu ana. Ā, ko tētahi kukūtanga tiaki i tētahi wāhanga ehara i te horopeta mō tētahi atu.

Kia pakari ake te taunakitanga, me whai wāhanga motuhake: he pānga matū ki te retina kua tautuhia i muri i te tuku mā tētahi ara ka taea te whakamahi haumanu, he inenga whakamutunga mō te mahi kite i ngā kararehe, he painga kāore e whakawhirinaki ki te pēhanga i tētahi tauira e hāngai ana ki te papahewa, kātahi ko ngā raraunga haumaru me te whai huatanga i te tangata. Kia puta rā anō aua taunakitanga, ka noho te hononga o te kikorangi metilīni me te kite hei whakapae rangahau whai rohe mārama: he mahi matū i ngā mitokōria o te retina e whai take ana, kua whakaaturia i ngā pūtau me ngā kararehe anake, ā, kāore he ara mai i ēnei rangahau ki te maimoatanga kanohi.