Ersin FADILLIOĞLU, Hasan ERDOĞAN, Memet Hanifi EMRE

Xanthine oxidase and adenosine deaminase activities of renal tissue in rats with hypertension induced by N sup omega nitro-L-arginine methyj ester

Hipertansiyon böbrek fonksiyonlarını negatif yönde değiştirebilir. Pürin metabolizması hipertansiyondan dolayı olan kan damarlarıdaki daralmadan ve artan kalp atım hacminden etkilenebilir. Nitrik oksit sentazın (NOS) N sup omega Nitro-L-Arjinin Metil Ester (L-NAME) ile inhibisyonu sıçanlarda hipertansiyona yol açar. Bu çalışmanın amacı NOS inhibisyonu sonrası sıçanlarda renal doku adenozin deaminaz (AD) ve ksantin oksidaz (XO) aktivitelerini araştırmaktı. Sıçanlar üç gruba ayrıldı; biri kontrol ve diğerleri 15 gün süreyle içme sularında 100 veya 500 mg/L L-NAME uygulanan çalışma gruplarıydı. Yukarda açıklanan uygulamanın sonunda, anesteziye edilen sıçanlarda karotid arter kanülasyonu yoluyla arteryel kan basınçları ölçüldü. Renal dokuda AD ve XO aktiviteleri ölçüldü. Sistolik kan basınçları L-NAME gruplarında anlamlı artiş gösterdi. L-NAME gruplarındaki XO aktivitesi, kontrol grubuyla karşılaştırıldığında anlamlı olarak artmıştı. AD aktiviteleri de L-NAME gruplarında artmış olmasına karşın, bu artış anlamlı bulunmadı. 100 mg ve 500 mg L-NAME grupları arasında XO ve AD aktiviteleri açısından anlamlı fark yoktu. Sonuçta, L-NAME ile indüklenen hipertansiyonun pürin nükleotidlerinde artışa neden olduğu kanısına vardık. Böylece, artmış XO ve AD enzim aktiviteleri sonucu birikmiş pürin nükleotidleri renal dokudan uzaklaştırılabilinir.

N sup omega nitro-L-arjinin metil ester ile indüklenen hipertansiyonlu sıçanların renal doku ksantin oksidaz ve adenozin deaminaz aktiviteleri

Hypertension may alter kidney functions negatively. Purine metabolism may be affected from constricted blood vessels and increased cardiac output, because of hypertension. Nitric oxide synthase (NOS) inhibition by N sup omega Nitro-L- Arginine Methyl Ester (L-NAMK) produces hypertension in rats. The aim of this study was to investigate adenosine deaminase (AD) and xanthine oxidase (XO) activities of renal tissue in rats after NOS inhibition. Rats were divided into three groups; one of them was control group and the others were study groups treated with 100 or 500 mg per liter L-NAME in drinking tap water for 15 days. After above-mentioned treatment, arterial blood pressure was measured via carotid artery cannula on anaesthetised rats. Activities of AD and XO were carried out in the renal tissue. Systolic blood pressures showed significant increase in both L-NAME groups. XO activities of L-NAME groups were increased significantly compared to control group. Increased AD activities were also observed in L-NAME groups but this increase did not reach statistical significance. There was no significant difference in XO and AD activities between 100 mg and 500 mg L-NAME groups. In conclusion, we speculated that hypertension induced by L-NAME causes increased purine nucleotides. Then, accumulated purine nucleotides may be removed from the renal tissue by increased XO and AD enzyme activities.

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