Bradykinin Antagonists Reduce Leukocyte???Endothelium Interactions After Global Cerebral Ischemia

Author(s):  
Jens Lehmberg ◽  
J??rgen Beck ◽  
Alexander Baethmann ◽  
Eberhard Uhl
2003 ◽  
Vol 23 (4) ◽  
pp. 441-448 ◽  
Author(s):  
Jens Lehmberg ◽  
Jürgen Beck ◽  
Alexander Baethmann ◽  
Eberhard Uhl

The aim of the present study was to evaluate the influence of bradykinin on microcirculatory changes and outcome after global cerebral ischemia (15 minute) in Mongolian gerbils. The cerebral microcirculation was investigated by fluorescent intravital microscopy. Survival and functional outcome was evaluated up to 4 d after ischemia. Animals were treated with the selective B1 and B2 receptor antagonists B 9858 and CP 0597, respectively, and the nonselective B1/B2 receptor antagonist B 9430. Leukocyte activation was significantly reduced by all antagonists as indicated by a significant decrease in the number of rolling (33 ± 20, 6 ± 8, 9 ± 10, and 13 ± 10) and adherent leukocytes (9 ± 7, 3 ± 4, 1 ± 1, and 2 ± 3 · 100 μm–1 · min–1 in controls and in animals treated with B1, B2, and B1/B2 antagonist, respectively). Arteriolar diameters were significantly reduced during reperfusion (35 ± 11 before and 27 ± 8 μm 40 minutes after ischemia) in animals treated with the B2 antagonist. The postischemic hypoperfusion, however, was not affected. Mortality was significantly higher in animals treated with the B1 and the B1/B2 antagonist. The authors concluded that bradykinin is involved in postischemic disturbances of cerebral microcirculation. The therapeutic effect of specific bradykinin receptor antagonists on functional outcome, however, remains unclear.


Author(s):  
R.V.W. Dimlich ◽  
M.H. Biros

In severe cerebral ischemia, Purkinje cells of the cerebellum are one of the cell types most vulnerable to anoxic damage. In the partial (forebrain) global ischemic (PGI) model of the rat, Paljärvi noted at the light microscopic level that cerebellar damage is inconsistant and when present, milder than in the telencephalon, diencephalon and rostral brain stem. Cerebellar injury was observed in 3 of 4 PGI rats following 5 minutes of reperfusion but in none of the rats after 90 min of reperfusion. To evaluate a time between these two extremes (5 and 90 min), the present investigation used the PGI model to study the effects of ischemia on the ultrastructure of cerebellar Purkinje cells in rats that were sacrificed after 30 min of reperfusion. This time also was chosen because lactic acid that is thought to contribute to ischemic cell changes in PGI is at a maximum after 30 min of reperfusion.


Author(s):  
К.А. Никифорова ◽  
В.В. Александрин ◽  
П.О. Булгакова ◽  
А.В. Иванов ◽  
Э.Д. Вирюс ◽  
...  

Цель. Установить влияние неспецифического адреноблокатора карведилола на редокс-статус низкомолекулярных аминотиолов (цистеин, гомоцистеин, глутатион) в плазме крови при моделировании глобальной ишемии головного мозга у крыс. Методика. Нами была использована модель глобальной ишемии (пережатие общих сонных артерий с геморрагией длительностью 15 мин). Препарат вводили за 1 ч до операции. Уровни аминотиолов измеряли через 40 мин после начала реперфузии. Анализ уровня аминотиолов проводили методом жидкостной хроматографии. Результаты. Установлено, что у крыс, не подвергавшихся ишемии, карведилол в дозе 10 мг/кг вызывает рост редокс-статуса цистеина и глутатиона (в 3 и 3,5 раза соответственно по сравнению с контролем, p = 0,04 и p = 0,008) за счет увеличения их восстановленных форм. При ишемии данного эффекта не наблюдалось. Редокс-статус у крыс с ишемией на фоне карведилола (Цис = 0,85 ± 0,14%, Глн = 1,8 ± 0,7%, Гцис = 1,1 ± 0,8%) оставался таким же низким, как и у крыс с ишемией без введения карведилола (р > 0,8). Заключение. Полученный результат демонстрирует, что в условиях ишемии головного мозга карведилол не оказывает эффекта на гомеостаз аминотиолов плазмы крови, несмотря на выраженный антиоксидантный эффект в нормальных условиях. Aim. Effect of a nonspecific adrenergic antagonist carvedilol on the redox status of plasma low-molecular-weight aminothiols (cysteine, homocysteine, glutathione) was studied in rats with global cerebral ischemia (occlusion of common carotid arteries with hemorrhage). Methods. A model of global ischemia (occlusion of common carotid arteries with 15-min hemorrhage) was used. The drugs were administered one hour before the operation. Aminothiol levels were measured by HPLC with UV detection at 40 minutes after the onset of reperfusion. Results. Carvedilol 10 mg/kg increased the redox status of cysteine and glutathione in rats not exposed to ischemia (3 and 3.5 times, respectively, compared with the control, p = 0.04 and p = 0.008, respectively) but not of homocysteine, by increasing their reduced forms. However, this effect was not observed in ischemia. In rats with ischemia treated with carvedilol, the redox status (Cys = 0.85 ± 0.14%, GSH = 1.8 ± 0.7%, Hcys = 1.1 ± 0.8%) remained low similar to that in rats with ischemia not treated with carvedilol (p >0.8, 0.8, and 0.9, respectively). Conclusion. Carvedilol did not affect the homeostasis of blood plasma thiols in cerebral ischemia despite the pronounced antioxidant effect under the normal conditions.


Author(s):  
Amteshwar Singh Jaggi

Aim: The aim of the present study is to explore the neuroprotective effects of remote ischemic preconditioning in long term cognitive impairment after global cerebral ischemia induced-vascular dementia in mice. Material and methods: The mice were subjected to global cerebral ischemia by occluding the bilateral common carotid arteries for 12 minutes followed by the 24 hours of the reperfusion. The remote ischemic preconditioning stimulus was delivered in the form of 4 cycles of ischemia/reperfusion for 5 minutes each. The cerebral ischemic injury induced-long term cognitive impairment-related learning and memory alterations was assessed using morris water maze, the motor performances of the animals were evaluated using rota-rod test and neurological severity score. The cerebral infract size of the brain were quantified using triphenyltetrazolium chloride staining. Results: Global cerebral ischemia causes long term memory impairment, decreases motor performances and increases the brain infract size in animals. The delivery of remote ischemic preconditioning stimulus significantly abolished the long-term cognitive impairment and ameliorates the motor performances as well as cerebral infract size in brain. Conclusion: The remote ischemic preconditioning mediates neuro protection against global cerebral ischemic injury induced long-term cognitive impairment.


2012 ◽  
Vol 14 (1) ◽  
pp. 20-35 ◽  
Author(s):  
Jake T. Neumann ◽  
Charles H. Cohan ◽  
Kunjan R. Dave ◽  
Clinton B. Wright ◽  
Miguel A. Perez-Pinzon

2021 ◽  
Vol 113 ◽  
pp. 101941
Author(s):  
Takayuki Nakajima ◽  
Yuji Kunieda ◽  
Yusuke Takahashi ◽  
Yuki Tanaka ◽  
Tomohiro Kondo ◽  
...  

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