Role of carotid body for neuronal protection in experimental subarachnoid haemorrhage

Abstract

Objective: Carotid bodies are known as main arterial chemoregulatory units. Despite well known that carotid bodies have an important role in cerebral circulation and blood pH regulation, their roles has not been investigated in subarachnoid haemorrhage. We investigated whether there is neuroprotective effect of neuron density of carotid bodies on the brain in subarachnoid haemorrhage. Methods: Twenty hybrid rabbits were studied. Four of them were used as reference group (n=4) and the remaining was obliged to subarachnoid haemorrhage by injecting autologous blood into their cisterna magna (n=16) and sacrificed after one month. All carotid bodies and brains examined histopathologically using by stereologic methods. The relationship between the neuronal density of carotid body and degenerated neuron density of the hippocampus were compared statistically. Results: Five rabbits with subarachnoid haemorrhage dead during the follow-up time (n=5). The average neuronal density of carotid body was 4500±500 cells/mm3 and of hippocampus 170.000±17.000 cell/mm3 in normal rabbit family. The degenerated neuron density of the hippocampus was 20.000±3.000 cells/mm3 in rabbits with have high neuron density of carotid body and was 65.000±8.000 cells/mm3 in rabbits with low neuron density of carotid body. The differences between the neuronal density of carotid body and the degenerated neuron numbers of the hippocampus were significant. Conclusion: The neuron density of carotid body may play an important role on the protection of brain in subarachnoid haemorrhage.

Keywords

• Subarachnoid haemorrhage, carotid body, hippocampus, neurodegeneration, cerebral ischemia

Deneysel subaraknoid kanamada karotid cismin nöron korumasındaki rolü

Abstract

Amaç: Karotid cisimler, temel arteriyel kemoregulatuar üniteler olarak bilinirler. Karotid cisimlerin serebral sirkülasyonda ve kan pH regülasyonunda önemli bir rolü olduğu iyi bilinmesine rağmen, subaraknoid kanamadaki rolleri henüz araştırılmamıştır. Biz subaraknoid kanamada karotis cisim nöron yoğunluğunun beyin üzerinde nöron koruyucu etkisinin olup olmadığını araştırdık. Yöntemler: Yirmi hibrit tavşan çalışmada kullanıldı. Bunların dört tanesi (n=4) referans grup olarak kullanıldı ve kalanların (n=16) sisterna magna\'ları içerisine otolog kan enjeksiyonu yapılarak subaraknoid kanama geliştirildi ve bir ay sonra hayvanların yaşam süresi sonlandırıldı. Tüm karotid cisim ve beyin dokuları, stereolojik metodlar kullanılarak histopatolojik olarak incelendi. Karotid cisimdeki nöronal yoğunluk ile hipokampustaki dejenere nöron yoğunluğu arasındaki ilişki istatistiksel olarak karşılaştırıldı. Bulgular: Subaraknoid kanaması olan beş tavşan takip süresi içerisinde öldü (n=5). Normal tavşan ailesinde karotid cisim ortalama nöronal hücre yoğunluğu 4500±500/mm3 ve hipokampus ortalama nöronal hücre yoğunluğu 170,000±17,000/mm3 olarak saptandı. Karotid cisminde yüksek nöron yoğunluğu olan tavşanların hipokampuslarındaki dejenere nöron hücre yoğunluğu 20,000±3,000/mm3 iken karotid cisminde düşük nöron yoğunluğu olan tavşanların hipokampuslarındaki dejenere nöron hücre yoğunluğu 65,000±8,000/mm3 saptandı. Karotid cismin nöronal yoğunluğu ve hipokampusun dejenere nöron sayıları arasındaki farklılık istatistiksel olarak anlamlıydı. Sonuç: Karotid cismin nöron yoğunluğu, subaraknoid hemorajide beyin dokusunun korunmasında önemli bir rol oynayabilir.

Keywords

• Subaraknoid hemoraji, karotid cisim, hipokampüs, nörodejenerasyon, serebral iskemi

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