No abstract

Çok eski zamanlardan beri varlığı bilinmesine rağmen pineal bezden salgılanan temel hormon olan melatoninin biyosentezi ve kimyasal yapısı ancak 1958'de Lerner tarafından ortaya konulabilmiştir. Melatonin gece boyunca en yüksek konsantrasyonda organizmada karşılaşılan sirkadiyen düzenleme ve uyku kontrolünden sorumludur. Kanda sirkadiyen bir ritim gösterir, gece değerleri ise gündüz seviyelerinden oldukça yüksektir. Melatoninin diğer önemli fonksiyonunun son derece güçlü serbest bir radikal temizleyici olduğu düşünülmektedir. Melatonin hem reaktif oksijen türlerini hem de reaktif azot türlerini etkisiz hale getirebilir. Melatoninin aynı zamanda çok toksik olan hidroksil radikalini, peroksi nitrit anyonu ve peroksil radikalini yakaladığı bilinmektedir. Melatonin bazı yerlerde bir prooksidatif enzim olan nitrik oksit sentetazı da inhibe etmektedir. Ayrıca süperoksit dismutaz enzimi için mRNA düzeyini sitümüle etmekte ve glutatyon peroksidaz, glutatyon redüktaz ve glukoz-6 fosfat dehidrojenazı aktive ettiği de bilinmektedir. Derlemenin amacı hem in vivo hem de in vitro yapılan deneyler sonucunda melatoninin çok güçlü bir antioksidan olduğunun önemini bir kez daha vurgulamaktır.

No abstract

Today, many factors such as advancing technology, environmental pollution, radiation, contaminated water, pesticides, heavy metals, stress and oxygen metabolism in living cells inevitably cause the formation of free radicals in the human body. Free radicals are very reactive forms of oxygen that destroy the cells of the organism. This calls for cardiovascular disease, cancer, cataracts, diabetes and many more diseases. To provide solutions to these diseases, firstly, we can eliminate the negative effects of free radicals and prevent the formation of diseases. While there is an antioxidant defense system in the human body that can prevent this, the environmental factors encountered break down this defense resistance and sometimes make it inadequate. We can strengthen our weakened antioxidant defense systems by eating a natural and balanced diet and consuming fruits and vegetables containing antioxidants, thus preventing illness. Research shows that free radicals have a significant effect on aging, free radical damage can be controlled with adequate antioxidant defense, and optimal antioxidant nutrient intake can contribute to improved quality of life. This review is intended to highlight once again the importance of alternative antioxidants in the body to eliminate free radicals and their harmful effects.

Human�s milk and cow�s milk fed-infants, long before the mother is exposed heavy metals are potentially dangerous for both mother and baby. Concentrations of toxic heavy metals (Pb, Cd, As) and major nutritional trace element (Zn) which collected center Bitlis, Tatvan and various villages in the 75 volunteer nursing mothers received 6 months after the birth human�s milks and 75 cow milks were analyzed. This study was measured by Inductively Coupled Plasma-Mass Spectrometer. Work was measured in accredited laboratory. In the samples As and Cd were under detectable leves although Zn and Pb were measured. Survey conducted, Zn and Pb levels in the mother milk which collected Tatvan borough were determined the highest. The all metal levels in the mother milk and cow milk which collected Bitlis center higher than villages. Zn levels in the cow milks which collected Bitlis center the highest. As a results of analysis, the avarege values of the lead in the human milks respectively (Bitlis center, Tatvan borough and villages) were found 0.0003�0.00004 mg/kg, 0.00045�0.000052 mg/kg, 0.0002�0.00003 mg/kg; the avarege values of the zinc 3.2�0.64 mg/kg, 3.34�0.57 mg/kg, 2.5�0.37 mg/kg. The avarege values of the lead in the cow milks respectively (Bitlis center, Tatvan borough and villages) were found 0.002�0.0004 mg/kg, 0.003�0.0004 mg/kg, 0.001�0.0003 mg/kg; the avarege values of the zinc 3.7�0.51 mg/kg, 3.6�0.49 mg/kg, 3.0�0.41 mg/kg. As a results of analysis between groups weren�t found significant relationship (P]0.05).