Ahmet ALİM, Meltem Rüyam DEMİRKOL, İlhan SEZGİN

3-Metilkolantren ve bütil hidroksitoluenle uyarılmış rat akciğer dokularında p-53 ekson 8 geni mutasyon analizi

Amaç. Bu çalışmada, gıda katkı maddesi olarak kullanılan Bütillenmiş hidroksitoluen (BHT)insadece kendisinin ve ayrıca BHTnin bir kimyasal karsinojen olan 3-Metilkolantren (3-MC) ilebirlikte uyğulandığında rat akciğerlerindeki karsinojen potansiyelleri ve p53 ekzon 8 geniüzerindeki mutasyon etkisinin incelenmesi amaçlanmıştır. Yöntem. Bu çalışmada 52 erkek ratkullanılmıştır. Deneye alınan birinci gruptaki (D1 grubu) 15 rata, 6 kez 3-MC (40 mg/kg/hafadozda ip yolla) uygulanmıştır. Deneye alınan ikinci gruptaki (D2 grubu) 15 rata tek doz 40 mg/kg3-MC ve ardından 6 kez BHT (200 mg/kg/hafta dozda ip yolla) uygulanmıştır. Deneye alınanüçüncü gruptaki (D3 grubu) 12 rata, sadece 6 kez BHT (200 mg/kg/hafta ip yolla) uygulanmıştır.Ayrıca 10 rattan oluşan bir kontrol grubu kullanılmıştır. Ratlar 26 hafta beklenildikten sonraservikal dislokasyon ile öldürülmüştür. Akciğerler sintigrafik, radyolojik ve morfolojik olarakdeğerlendirilmiştir. Bütün grupların akciğer dokusundan DNA izolasyonu yapılmış ve buDNAlardan, P53 geni ekson 8 amplifkasyonu Polimeraz Zincir Reaksiyonu (PCR) ürünlerindeSingle-Strand Conformation Polimorphism (SSCP) analizi yapılarak, nokta mutasyonu taramasıyapılmıştır. Bulgular. Bu çalışmaların sonucunda radyolojik, sintigrafik, morfolojik ve genetikdüzeyde ratların akciğerinde kanser oluşumu tespit edilememiştir. Fakat ratlara kimyasalmaddelerin uygulanım yerinde yumuşak doku kaynaklı sarkom gelişimi tespit edilmiştir. Yapılanmutasyon taramasında P53 geni ekson 8de bir mutasyon bulunamamıştır. Sonuç. Her ne kadarçalışmamızda ratlarda kanser oluşumu tespit edemesekte, uygun doz ve zaman uyumlu 3-MC veBHT uygulayarak, özellikle tümör oluşumuna duyarlı fare türleri kullanarak çalışmanın uygunolacağı düşünülmüştür.

Analysis of p-53exon 8 gene mutations in 3-methylcholanthrene and butylated hydroxytoluene-induced rat lung tissues

Aim. In this study we aimed to detect the carcinogenic effects on lungs of rat and, also themutation effects on P53 ekzon 8 gene of Butylated hydroxytoluene (BHT) and BHT together with3-Metilkolantren (3-MC) which is a carcinogenic chemical substance. Method. In this study, 52male rats were used. 15 rats in the first group (D1) are administered 3-MC i.p 40 mg/kg per weekduring 6 weeks. 15 rats in the second group (D2) were given a single dose of 3-MC i.p. 40 mg/kgand subseguently BHT 200 mg/kg of body weight per week for 6 weeks. 12 rats in the third group(D3) were exposed to BHT 200 mg/kg of body weight on weekly basis for 6 weeks. 10 rats inControl (c) group were only given corn oil in which both 3-MC and BHT are soluable, for 6 weeksreceiving 100 l for each shot. The rats were killed with cervical dislocation at the end of 26weeks. Lung tisues were evaluated by scintigraphic, radiologic and morphologic methods. DNAisolation was carried out tissues of the lungs followed by Polymerase chain reaction (PCR)amplification for exon 8 of p53 gene. Then, in the PCR products mutational analysis was carriedout using Single-Strand Conformation Polimorphism (SSCP) technique. Results. Cancerdevelopment has not been detected in lung tissues of the rats that were exposed to 3-MC and BHT.However, it has been found that subcutaneous soft tissue sarcomas were detected at the applicationsite of carcinogens. In p53 gene exon 8 screening, there is no mutation were technique found in thelung tissues of all rats. Conclusion. Although we could not detect any cancer formation in our rats,we think that using appropriate dose and timing of 3-MC and BHT in especially cancer sensitiverats is convenient.

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