Gülinnaz ALPER, Yıldırım Eser SÖZMEN, Girgin Ferhan SAĞIN, İlknur YANTURALI, LÜTFİYE KANIT, Biltan ERSÖZ

Monoamin oksidaz aktivitesi ve nitrik oksit düzeyleri beynin değişik bölgelerinde cinsiyetle ilişkili değişim gösterir

Kuş ve memeli hayvanların beyinlerinde morfolojik cinsiyet farklılıklarının keşfi, beynin değişik bölgelerine seks-streroidlerinin olası etkileri konusunda ileri araştırmalara yol açmıştır. Bizim çalışmamızın da amacı, cinsiyetler arasında belirgin bir fark olup olmadığını ortaya koyabilmek için farklı beyin bölgelerindeki MAO aktivitelerini ve NO düzeylerini araştırmaktır. Sonuçlarda, hem erkek (n=8) hem dişi (n=8) Sprague-Dawley sıçanlarda, MAO aktivitesi amigdalada en düşük, kodekste en yüksek, hipotalamusta ise dişilerde daha yüksek bulundu. Total nitrit-nitrat seviyeleri en yüksek hipotalamusta saptanırken, bunu amigdala takip etti. Nitrit seviyeleri dişilerde yüksekken, nitrat ve total nitirt-nitrat seviyeleri açısından tüm beyin bölgelerinde erkeklerle dişiler arasında fark bulunamadı. Dişi serebellumunda MAO aktivitesi ile nitrit seviyeleri arasında negatif korelasyon izlendi. Bu çalışma MAO aktivitesi ile ilişkili olarak beyin NO seviyelerinde cinsiyete bağlı bölgesel farklılıkların kanıtlarını ortaya koyması açısından ilk bildiridir. Bu cinsiyete bağlı farklılıkların, nörodejeneratif hastalıklar ve MAO inhibitörleri ile seks-steroidleri ile tedavi yaklaşımları hakkında ileri araştırmalar yapılırken göz önüne alınması yararlı olabilir.

Anahtar Kelimeler:

Nitrik oksit, Monoamin oksidaz, Hipotalamus, Beyin, Cinsiyet gelişimi, Modeller, hayvan, Sıçan, Sprague-Dawley

Monoamine oxidase activity and nitric oxide levels vary between different brain regions in a gender specific way

The discovery of morphological sex differences in bird and mammal brains led to extensive research on the possible effects of sex steroids on different areas of the CNS. The aim of our study was to investigate MAO activity and NO levels in different brain regions in order to determine whether there are any significant differences between sexes. MAO activity was lowest in amygdala and highest in the cortex in both male (n=8) and female (n=8) Sprague-Dawley rats, while it was found to be higher in the female hippocampus. Hypothalamus had the highest total nitrite-nitrate levels and was followed by the amygdala. While nitrite levels were higher in females, nitrate and total nitrite-nitrate levels were similar in all brain regions in both sexes. In the female cerebellum a (-) correlation between MAO activity and nitrite levels could be noted. Current study is the first report providing evidence on sex related regional differences in brain NO levels with respect to MAO activity. These gender specific variations might be taken into consideration for further research studies underlying neurodegenerative disorders and therapeutic strategies using MAO inhibitors as well as sex steroids.

Keywords:

Nitric Oxide, Monoamine Oxidase, Hypothalamus, Brain, Sex Differentiation, Models, Animal, Rats, Sprague-Dawley,

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