Erkek ve dişi ratlarda cuprizone ile oluşturulan demiyelinsayon ve remiyelinasyonun elektromiyografik özelliklerinin incelenmesi
The investigation of the effect of cuprizone (CP) induced demyelination and remyelination on electromygraphic characteristics of male female rats
Yazar: CENGİZ ÜNSAL
Danışman: PROF. DR. MUKADDES ÖZCAN
İstanbul Üniversitesi / Sağlık Bilimleri Enstitüsü / Fizyoloji Ana Bilim Dalı
Derece: Doktora, 2004
Konu: Fizyoloji = Physiology

Özet:
8. ÖZET Bu çalışmada erkek ve dişi ratlarda cuprizone (CP) ile oluşturulan demiyelinasyon ve remiyelinasyonun elektromiyografik özelliklere etkileri incelendi. Çalışmada toplam 108 adet üç aylık dişi ve erkek Sprague Dawley rati kullanıldı ve iki deney yapıldı. İlk deneyde dört haftalık demiyelinasyon periyodundaki değişimler incelendi. İkinci deneyde dört haftalık demiyelinasyon periyodunu takip eden sekiz haftalık remiyelinasyon periyodundaki değişimler araştırıldı. CP (Fluka®) toz halindeki rat yemine %1 oranında ilave edildi. Yem ve su ad libitum verildi. Aynı yaş grubundan CP almayan hayvanlar kontrol grubu olarak belirlendi. Demiyelinasyon ve remiyelinasyon periyodlarmda vücut ağırlığı, yem tüketimi, sinir iletim hızı (NCV) ve latans ölçümleri haftalık yapıldı. Doku örnekleri demiyelinasyon ve remiyelinasyon periyodlan için sırasıyla her hafta ve iki haftada bir olacak şekilde alındı. Merkezi ve perifer sinir sisteminin histopatolojik incelemeleri için korpus kallozum, superior serebellar pedinkül ve siyatik sinirden seri kesitler yapıldı. LFB-PAS ile boyanan doku örnekleri ışık mikroskobunda değerlendirildi. Elektromiyografik ölçümlerde BIOPAC® MP 30 Ultimate System kullanıldı. Siyatik sinirin ortodromik stimülasyonundan sonra gastroknemius kasına bağlanan yüzey elektrodlanyla kaydedildi. Elektromiyografik sinyal güçlendirildi (kazanç 2500, band aralığı 0.5 Hz-5kHz) ve bilgisayarda 25 kHz örnekleme hızında görüntülendi. Veriler Biopac BSL Pro Software (Version 3.6.7) ile incelendi. İlk deneyde, CP nörotoksitesi tüm deney gruplarında birinci haftadan itibaren yem tüketimi ve vücut ağırlığında azalmaya neden oldu. Yem tüketimi ve vücut ağırlığındaki azalma deney boyunca gözlendi. Dört haftalık bu demiyelinasyon periyodunda genel olarak deney gruplarında NCV'nin azaldığı, latansın ise arttığı saptandı. Bu süreçte sinir iletim hızı ve latans değerleri dişi ve erkek ratlar arasında farklılıklar gösterdi. Sekiz haftalık remiyelinasyon sürecinde erkek ratların vücut ağırlığı kontrol grubuna göre ilk üç haftada farklılık gösterirken, dişi ratlarda bu farklılık sadece birinci haftada gözlendi. Her iki cinsiyette de NCV kademeli olarak arttı ve sekizinci haftada normal değerlerine ulaştı. Histopatolojik incelemeler dişi ve erkek ratlarda demiyelinasyonun oluştuğunu ve erkek ratlarda bu değişimlerin daha belirgin olduğunu ortaya koymaktadır. 64Anahtar kelimeler: Cuprizone, rat, demiyelinasyon, remiyelinasyon, sinir iletim hızı, latans 9. SUMMARY The investigation of the effect of cuprizone (CP) induced demyelination and remyelination on electromyographic characteristics of male and female rats The aim of the present study was to examine the effect of an experimental demyelination and remyelination induced by cuprizone (CP) on electromyographic characteristics of female and male Sprague Dawley rats. A total of 108 3-months old male and female Sprague Dawley rats were used. For this reason, two experiments were designed. In the first experiment, changes within the four-week demyelination period were examined. In the second experiment, changes within the eight-week remyelination period following the four-week demyelination period were examined. CP (Fluka®) was added to rat chow powder diet at a concentration of 1 %. Food and water was given ad libitum. Animals of the same age group receiving no CP served as control. Body weight, food consumption, nerve conduction velocity (NCV) and latency were measured weekly throughout the demyelination and remyelination periods. Serial sections were taken from corpus callosum, superior cerebellar pedincule and sciatic nerve for histopathologic examination of central and peripheral nervous systems. Tissue samples were taken weekly and biweekly during the demyelination and remyelination periods, respectively, sections were stained by LFB-PAS and evaluated under the light microscope. Electromygraphic measures were taken using the BIOPAC® MP 30 Ultimate System. Response of gastrocnemius muscle was recorded using a surface electrode after stimulating the sciatic nerve orthodromically. The electromyographic signal was amplified (gain 2500, bandwith 0.5 Hz-5 kHz) and digitized at 25 kHz sampling rate by computer and the data was analyzed with the Biopac BSL Pro software (Version 3.6.7). In the first experiment, CP induced neurotoxicity reduced food consumption and body weight from the first week onwards in all experimental groups. Reductions in food consumption and body weight were observed throughout the experimental period. In the experimental groups, NCV decreased and latency increased 65

Abstract:
Anahtar kelimeler: Cuprizone, rat, demiyelinasyon, remiyelinasyon, sinir iletim hızı, latans 9. SUMMARY The investigation of the effect of cuprizone (CP) induced demyelination and remyelination on electromyographic characteristics of male and female rats The aim of the present study was to examine the effect of an experimental demyelination and remyelination induced by cuprizone (CP) on electromyographic characteristics of female and male Sprague Dawley rats. A total of 108 3-months old male and female Sprague Dawley rats were used. For this reason, two experiments were designed. In the first experiment, changes within the four-week demyelination period were examined. In the second experiment, changes within the eight-week remyelination period following the four-week demyelination period were examined. CP (Fluka®) was added to rat chow powder diet at a concentration of 1 %. Food and water was given ad libitum. Animals of the same age group receiving no CP served as control. Body weight, food consumption, nerve conduction velocity (NCV) and latency were measured weekly throughout the demyelination and remyelination periods. Serial sections were taken from corpus callosum, superior cerebellar pedincule and sciatic nerve for histopathologic examination of central and peripheral nervous systems. Tissue samples were taken weekly and biweekly during the demyelination and remyelination periods, respectively, sections were stained by LFB-PAS and evaluated under the light microscope. Electromygraphic measures were taken using the BIOPAC® MP 30 Ultimate System. Response of gastrocnemius muscle was recorded using a surface electrode after stimulating the sciatic nerve orthodromically. The electromyographic signal was amplified (gain 2500, bandwith 0.5 Hz-5 kHz) and digitized at 25 kHz sampling rate by computer and the data was analyzed with the Biopac BSL Pro software (Version 3.6.7). In the first experiment, CP induced neurotoxicity reduced food consumption and body weight from the first week onwards in all experimental groups. Reductions in food consumption and body weight were observed throughout the experimental period. In the experimental groups, NCV decreased and latency increased 65generally in the four-week demyelination period. There were differences in nerve conduction velocity and latency between male and female rats in this period. In the eight-week remyelination period, body weights of female rats differed from that of control animals only for the first week, whereas body weights of male rats were significantly different from that of control animals for the first three-week. NCV gradually increased in both sexes and reached to its normal values by the eighth week. Histopathological analyses revealed that demyelination was present in both sexes, and these changes were observed to be more prominent in male rats. Key words: Cuprizone, rat, demyelination, remyelination, nerve conduction velocity, latency. 10. KAYNAKLAR 1. Adams, RD, Victor M, Ropper AH. Principles of Neurology. McGraw-Hill, USA. 1997; 1286-1301. 2. Akassoglou K, Bauer J, Kassiotis G, Pasparakis M, Lassmann H, Kollias G, Probert L. Oligodendrocyte apoptosis and primary demyelination induced by local TNF/p55TNF receptor signaling in the central nervous system of transgenic mice models for multiple sclerosis with primary oligodendrogliopathy. Am J Pathol 1998; 153: 801-813. 3. Aktin E. Nörolojide Dünden Bugüne. Öge AE (ed). Nöroloji İÜ İstanbul Tıp Fakültesi Temel ve Klinik Bilimler Ders Kitapları. Nobel Tıp Kitapevi, İstanbul, 2004; 1-4. 4. Alley J, Khasabov S, Simone D, Beitz A, Rodriguez M, Njenga MK. More severe neurologic deficits in SJL/J male than female mice following Theiler's virus-induced CNS demyelination. Exp Neurol 2003; 180: 14-24. 5. Almazan G, Honegger P, Matthieu J-M, Guentert-Lauber B. Epidermal growth factor and bovine growth hormone stimulate differentiation and myelination of brain cell aggregates in culture. Dev Brain Res 1985; 21: 257-264. 6. Bakker DA, Ludwin SK. Blood brain barier permeability during cuprizone 66