Çocuklarda Kurşun Zehirlenmesi, Oksidatif Stres ve Tiyol Bileşiklerin Antioksidan Etkisi

Öz

Kurşun, endüstride yaygın olarak kullanılmasından dolayı büyük bir çevresel sorun oluşturmaktadır. Kronik kurşun zehirlenmesi ise dünya ülkeleri ve ülkemizde çocuklar için en önemli sağlık sorunlarından biridir. Çocuklar kolayca inhibisyona ve hasara uğrayabilen hücre farklılaşması ve büyümesine sahip, gelişen bir sisteme sahiptir. Kurşun zehirlenmesine karşı daha fazla miktarda kurşun absorbe ettikleri için de yetişkinlere göre daha duyarlıdırlar. Bununla birlikte, çok düşük miktarlardaki kurşun maruziyetinin sinirsel hasar, kavrama bozukluğu, nörodavranışsal hastalıklar, hipertansiyon ve böbrek yetmezliğine yol açtığı gösterilmiştir. Kurşunun tüm mekanizması oksidatif hasarla gelişmektedir. Kurşunla uyarılan oksidatif stres başlıca eritrositlerde görülür; hem ve hemoglobin Hb sentezinin önlenmesi, eritrosit morfolojisinin ve ömrünün değiştirilmesi ana etkilerdir. Sonuçta, biriken aminolevülinik asit ALA ise, reaktif oksijen türlerinin meydana gelmesine yol açar. Buna ilaveten kurşun fonksiyonel -SH grubu taşıyan birçok enzimi inhibe ederek ve oksidatif hasara neden olarak hücrelerin pro-oksidan/antioksidan dengesinde bir bozulma da meydana getirir. Deneysel çalışmalarda tiyollerin tek başlarına veya şelatör ajanlarla birlikte kurşunun zararlı etkilerine karşı yararlı olduğu gözlenmiştir. Bu ajanlar kurşunun bazı zehirli etkilerine karşı koyar ya da kurşun maruziyeti sonrası prooksidan/antioksidan oranındaki bozulmayı dengeler. Sülfür taşıyan metiyonin, N-asetilsistein NAC , α-lipoik asit ve homosistein gibi antioksidanların endüstriyel ortamda çalışan çocuk işçilerin ya da hava kirliliğinde yaşayan çocukların kurşun zehirlenmesine karşı korunmasındaki stratejilerde kullanılması yeni bir yaklaşımdır.

Anahtar Kelimeler

• Kurşun,oksidatif stres,antioksidan,α-lipoik asit,homosistein

Lead Toxication and Oxidative Stress in Children and Antioxidant Effects of Thiol Compounds

Öz

Lead causes a great environmental problem because it’s being widely used in the industry. Chronic lead intoxication is the most important health threat to children in the World and our country. Children have a developing system of cell differentiation and growth that’s more vulnerable to inhibition and damage. They’re far more susceptible to lead neurotoxicity than adults because they absorb a higher fraction of lead and. However, it has indicated that low-level exposures of lead result in neurological damage, cognitive dysfunction, neurobehavioral disorders, hypertension, and renal impairment. The mechanism all of lead has in common involves oxidative damage. Oxidative stress induced by lead is seen mainly in erythrocytes including inhibition of heme and hemoglobin Hb synthesis, and changing the erythrocytes morphology and survival. The accumulated aminolevulinic acid ALA induces ROS generation and lead also inhibits several enzymes having functional -SH groups and might cause impairment in prooxidant/antioxidant balance of cells, resulting in oxidative damage. Thiols either individually or in a combined therapy, with chelating agents have been observed to have beneficial effects against lead’s detrimental properties in experimental studies. These agents were found to be capable of abating some toxic effects of lead, or they are effective in rebalancing the impaired pro-oxidant/antioxidant ratio following lead exposure. It has been indicated that sulfur containing antioxidants, such as methionine, N-acetylcystein NAC , α-lipoic acid or homocysteine, have a novel approach to strategies for preventing for lead poisoning in industrial child workers or children living in airpollutions.

Anahtar Kelimeler

• Lead,oxidative stress,antioxidant,α-lipoic acid,homocysteine

Kaynakça

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