{"id":14320,"date":"2023-10-25T17:35:00","date_gmt":"2023-10-25T14:35:00","guid":{"rendered":"http:\/\/blog.ulubat.org\/?p=14320"},"modified":"2023-10-25T18:34:18","modified_gmt":"2023-10-25T15:34:18","slug":"uv-isinlar-ve-dogal-gunes-kremimiz-melanin","status":"publish","type":"post","link":"https:\/\/blog.ulubat.org\/index.php\/genel\/uv-isinlar-ve-dogal-gunes-kremimiz-melanin\/","title":{"rendered":"UV I\u015eINLAR VE DO\u011eAL G\u00dcNE\u015e KREM\u0130M\u0130Z MELAN\u0130N"},"content":{"rendered":"\n

G\u00fcn\u00fcm\u00fczde ten rengi \u00fczerinden k\u0131r\u0131l\u0131p g\u00fcndeme gelen sosyok\u00fclt\u00fcrel yans\u0131man\u0131n arkas\u0131ndaki g\u00f6r\u00fcnt\u00fc, G\u00fcne\u015f\u2019tir asl\u0131nda. Ten rengi varyasyonlar\u0131, G\u00fcne\u015f\u2019ten gelen UV (mor\u00f6tesi) \u0131\u015f\u0131nlar<\/strong> ve ilerleyen paragraflarda de\u011finece\u011fimiz melanin<\/strong> pigmenti aras\u0131ndaki pasla\u015fman\u0131n jenerasyonlar boyunca devam etmesiyle ortaya \u00e7\u0131km\u0131\u015ft\u0131r .<\/p>\n\n\n

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\u015eekil 1.<\/figcaption><\/figure><\/div>\n\n\n

UV I\u015f\u0131nlar\u0131n\u0131n Deri Pigmentasyonuna Etkisi<\/strong><\/h2>\n\n\n\n

UV \u0131\u015f\u0131nlar\u0131n\u0131n nam\u0131n\u0131, g\u00fcne\u015f kremlerinin koruyuculu\u011fu y\u00f6n\u00fcndeki tart\u0131\u015fmal\u0131 a\u00e7\u0131klamalardan biliyoruz. \u00a0K\u0131saca bahsetmek gerekirse yery\u00fcz\u00fcne ula\u015fan UV \u0131\u015f\u0131nlar\u0131n\u0131n %95\u2019ini olu\u015fturan UV-A, cam taraf\u0131ndan filtrelenmedi\u011fi i\u00e7in onu a\u015f\u0131p cilde derinlemesine n\u00fcfuz edebilir ve elastik dokuda y\u0131k\u0131ma neden olur. G\u00fcne\u015f yan\u0131klar\u0131ndan sorumlu olan ise, ozonla filtrelendi\u011fi i\u00e7in UV-A\u2019 ya nazaran yery\u00fcz\u00fcne daha az ula\u015fan UV-B\u2019dir. UV radyasyon (UVR), DNA\u2019dan elektron kopar\u0131p genleri de\u011fi\u015ftirecek kadar tehlikelidir. Peki ten rengi bu ana fakt\u00f6r\u00fcn etraf\u0131nda nas\u0131l desenlendi?<\/p>\n\n\n\n

 Homo sapiensin en eski \u00fcyeleri Afrika b\u00f6lgesinde ya\u015f\u0131yordu ve o zamanlar b\u0131rak\u0131n g\u00fcne\u015f kremini, giysi kullan\u0131m\u0131 bile olmad\u0131\u011f\u0131 i\u00e7in her an UVR\u2019ye maruz kalan bedenlerinde g\u00fc\u00e7l\u00fc bir se\u00e7ici bask\u0131yla kal\u0131c\u0131 koyu renkli pigmentasyon evrimle\u015fmi\u015fti. \u0130nsanlar zamanla tropik b\u00f6lgelerden uza\u011fa, Afrika’n\u0131n d\u0131\u015f\u0131na, daha d\u00fc\u015f\u00fck y\u0131ll\u0131k ortalama UVR’ye sahip b\u00f6lgelere girmi\u015flerdir. Azalan UV-B seviyeleri depigmentasyon (\u00e7evresel fakt\u00f6rlerle melanin azalmas\u0131) i\u00e7in pozitif se\u00e7ilim yaratm\u0131\u015ft\u0131r.<\/p>\n\n\n

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\u015eekil 2.<\/figcaption><\/figure><\/div>\n\n\n

Bu konuda yap\u0131lan analizler sonucunda ten renkleri ile UV radyasyonun yery\u00fcz\u00fcne d\u00fc\u015fme a\u00e7\u0131lar\u0131 aras\u0131nda bir korelasyon bulunmu\u015f ve bunun desenlendi\u011fi haritalar olu\u015fturulmu\u015f.<\/p>\n\n\n\n

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\u015eekil 3.
https:\/\/commons.m.wikimedia.org\/wiki\/File:UV_Index.png<\/a><\/figcaption><\/figure>\n<\/div>\n\n\n\n
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\u015eekil 4.
https:\/\/openi.nlm.nih.gov\/detailedresult?img=PMC3154201_pone.0022103.g002&req=4<\/a><\/figcaption><\/figure>\n<\/div>\n<\/div>\n\n\n\n

Haritalara bakt\u0131\u011f\u0131m\u0131zda ekvatora yak\u0131nl\u0131kla UV radyasyon yo\u011funlu\u011funun do\u011fru orant\u0131l\u0131 bir pattern \u00e7izdi\u011fini g\u00f6rebiliriz. Ten renginin da\u011f\u0131l\u0131m\u0131na bakt\u0131\u011f\u0131m\u0131zda da ayn\u0131 pattern g\u00f6r\u00fcl\u00fcyor. Ekvatora yak\u0131n b\u00f6lgelerde ya\u015fayan insanlar daha koyu cilde sahip.<\/p>\n\n\n\n

UV Radyasyon Kar\u015f\u0131s\u0131nda Melaninin Rol\u00fc<\/strong><\/h2>\n\n\n\n

DNA\u2019m\u0131zdaki elektronlar\u0131 koparacak kadar y\u00fcksek enerjili oldu\u011funu s\u00f6yledi\u011fimiz bu UVR\u2019ye kar\u015f\u0131 ilk savunma hatt\u0131 epidermisimizdeki melanosit h\u00fccreleridir. Bunlar\u0131n \u00fcretti\u011fi 2 \u00e7e\u015fit melaninden biri olan eumelanin, foto koruyucudur. Kahverengi ve siyah formlarda bulunur ve deri taraf\u0131ndan emilen UV-A ve UV-B radyasyonun b\u00fcy\u00fck bir k\u0131sm\u0131n\u0131 da\u011f\u0131tarak h\u00fccreleri bir \u015femsiye gibi korur. Melanosit h\u00fccreleri UVR\u2019yi bir tehdit olarak alg\u0131lad\u0131\u011f\u0131 i\u00e7in melanin \u00fcretimini artt\u0131r\u0131r ve b\u00f6ylece derinin rengi de koyula\u015f\u0131r. Yani asl\u0131nda bronzla\u015fma dedi\u011fimiz \u015fey; estetik bir kayg\u0131dan \u00e7ok uzakta, v\u00fccudun g\u00fcne\u015fe kar\u015f\u0131 verdi\u011fi bir savunma tepkisi, bir modifikasyondur. Ara\u015ft\u0131rmalara g\u00f6re koyu pigmentli derinin epidermisindeki toplam melanin i\u00e7eri\u011finin, a\u00e7\u0131k pigmentli deriye oranla 3-6 kat daha y\u00fcksek d\u00fczeyde ve melanozomlar\u0131n\u0131n da daha fazla ve b\u00fcy\u00fck oldu\u011fu bulunmu\u015ftur. (M. Brenner ve V.J Hearing, 2009). Epidemiyolojik veriler de g\u00f6steriyor ki deri pigmentasyonu ile g\u00fcne\u015f kaynakl\u0131 deri kanseri (melanom) insidans\u0131 aras\u0131nda ters korelasyon vard\u0131r. Yani a\u00e7\u0131k tenliler radyasyon hasar\u0131na daha duyarl\u0131 ve deri kanserine de \u00e7o\u011funlukla daha yatk\u0131n. Bu da melaninin foto-koruyucu rol\u00fcn\u00fc g\u00fc\u00e7l\u00fc bir \u015fekilde desteklemektedir. Bu konuda deri ve biyokimya profes\u00f6r\u00fc Dr. Anand Ganesan, \u2018\u2019Melanin, UV hasar\u0131n\u0131 \u00f6nlemek i\u00e7in do\u011fal bir g\u00fcne\u015f kremi gibi davranan bir pigmenttir. \u2018\u2019<\/em> der.<\/p>\n\n\n\n

 Sonu\u00e7ta melanin iyi ki var ama UVR\u2019nin g\u00f6z\u00fc karal\u0131\u011f\u0131 da ortadayken derimizi dolmal\u0131k biber kurutur gibi korumadan g\u00fcne\u015f alt\u0131na b\u0131rakmak \u00e7ok mant\u0131kl\u0131 de\u011fil gibi g\u00f6r\u00fcn\u00fcyor.<\/p>\n\n\n\n

KAYNAK\u00c7A<\/p>\n\n\n\n

1-Brenner M, Hearing VJ. The protective role of melanin against UV damage in human skin. Photochem Photobiol. 2008 May-Jun;84(3):539-49. doi: 10.1111\/j.1751-1097.2007.00226.x. PMID: 18435612; PMCID: PMC2671032.<\/p>\n\n\n\n

2-Jablonski, N. G. (2004). The evolution of human skin and skin color. Annu. Rev. Anthropol.<\/em>, 33<\/em>, 585-623.<\/p>\n\n\n\n

3-Jablonski, N. G., & Chaplin, G. (2010). Human skin pigmentation as an adaptation to UV radiation. Proceedings of the National Academy of Sciences<\/em>, 107<\/em>(supplement_2), 8962-8968.<\/p>\n\n\n\n

4- Lasisi, T., & Shriver, M. D. (2018). Focus on African diversity confirms complexity of skin pigmentation genetics. Genome biology<\/em>, 19<\/em>(1), 1-3.<\/p>\n\n\n\n

5-Lasisi, T. (2021). The constraints of racialization: How classification and valuation hinder scientific research on human variation. American Journal of Physical Anthropology<\/em>, 175<\/em>(2), 376-386.<\/p>\n\n\n\n

6-Tadokoro, T., Yamaguchi, Y., Batzer, J., Coelho, S. G., Zmudzka, B. Z., Miller, S. A., … & Hearing, V. J. (2005). Mechanisms of skin tanning in different racial\/ethnic groups in response to ultraviolet radiation. Journal of Investigative Dermatology<\/em>, 124<\/em>(6), 1326-1332.<\/p>\n","protected":false},"excerpt":{"rendered":"

Ten rengi varyasyonlar\u0131, G\u00fcne\u015f\u2019ten gelen UV (mor\u00f6tesi) \u0131\u015f\u0131nlar ve melanin pigmenti aras\u0131ndaki pasla\u015fman\u0131n jenerasyonlar boyunca devam etmesiyle ortaya \u00e7\u0131km\u0131\u015ft\u0131r. Ten renkleri ile uv radyasyonun yery\u00fcz\u00fcne d\u00fc\u015fme a\u00e7\u0131lar\u0131 aras\u0131nda bir korelasyon bulunmu\u015f ve bunun desenlendi\u011fi haritalar olu\u015fturulmu\u015f.<\/p>\n","protected":false},"author":1828,"featured_media":14338,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[2175,1],"tags":[2447,2450,2449,2425,147,2448,2446,2445],"acf":[],"views":87,"_links":{"self":[{"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/posts\/14320"}],"collection":[{"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/users\/1828"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/comments?post=14320"}],"version-history":[{"count":11,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/posts\/14320\/revisions"}],"predecessor-version":[{"id":14417,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/posts\/14320\/revisions\/14417"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/media\/14338"}],"wp:attachment":[{"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/media?parent=14320"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/categories?post=14320"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.ulubat.org\/index.php\/wp-json\/wp\/v2\/tags?post=14320"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}