Osman GENÇ, Şerif DEMİR, Niyazi TAŞÇI, Cafer MARANGOZ

Flunarizinin omurilik reflekslerine etkisi

Amaç: Spinal kedilerde kalsiyum kanal blokeri flunarizinin monosinaptik reflekslere etkisini araştırmak amaçlandı. Yöntem: Flunarizin 10, 50, 100 uM lokal ve 5, 10, 20 mg/kg intraperitoneal olarak verildi. 1.5-3 kg ağırlığında yetişkin 10 kedi ketamin (50 mg/kg, İM) ile anestezi edildi ve suni ventilasyon uygulandı. Hayvanlar servikal (C1) seviyeden spinalize edildi. Lumbosakral bölgede laminektomi yapıldı. L5 segmentin dorsal ve ventral kökleri izole edildi. Havuz oluşturuldu, dokular likit vazelinle örtüldü ve 38.5+0.5°C'de muhafaza edildi. Karotis artere polietilen kanül yerleştirilerek kan basıncı gözlendi ve 100 mmHg'nın üzerinde olması sağlandı. Stimülasyon için L5 segmentin dorsal köküne gümüş-gümüş klorür tel elektrod yerleştirildi. Refleks potansiyeller ipsilateral L5 ventral kökten kaydedildi, bu kayıtta da gümüş-gümüş klorür tel elektrod kullanıldı. Bulgular: Flunarizinin sistemik ve lokal dozları refleks cevap amplitüdünü anlamlı şekilde azalttı. Bununla birlikte, ilaç uygulamasından sonra monosinaptik reflekslerin latensi uzadı. Sonuç: Omurilikteki voltaja bağımlı kalsiyum kanalları refleks cevabın düzenlenmesinde önemli bir role sahip olabilir.

The effects of flunarizine on spinal reflexes in the cats

Objective: Effects of calcium channel blocker flunarizine on spinal monosynaptic reflexes were aimed to investigate in spinal cats. Methods: Flunarizine was administered locally into the spinal cord (10, 50, 100 u.M) and intraperitoneally (5, 10, 20 mg/kg). Adult cats (n=10) weighing 1.5-3 kg were anesthetized with ketamine (50 mg/kg, IM) and artificially ventilated. Animals were spinalized at C1 level. A laminectomy was performed in the lumbosacral region. The ventral and dorsal roots of segment L5 were isolated and a pouch of skin was formed at the site of the dissection to allow the exposed tissues to be covered with liquid paraffin. The temperature was kept at 38.5±0.5°C with a heating pad. A polyethylene cannula was introduced into the left carotid artery to monitor blood pressure which was kept above 100 mmHg. The dorsal root of segment L5 was placed on a silver- silver chloride wire electrode for stimulation through an isolation unit. Reflex potentials were recorded from ipsilateral L5 ventral root, mounted on a silver- silver chloride wire electrode. Results: The systemic and local doses of cinnarizine derivative flunarizine significantly decreased the amplitude of reflex response. Moreover, the latency of the monosynaptic reflexes increased after administration of the drug. Conclusion: Voltage-dependent calcium channels in the spinal cord may play an important role in regulation the reflex response.

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