[Effect of blocking angiotensin receptors on cerebral blood flow in the post-ischemic period in hypertensive rats]. / Vliianie blokady angiotenzinovykh retseptorov na mozgovoi krovotok v postishemicheskom periode u gipertenzivnykh krys.

Acute experiments on anesthetized rats have been conducted to study the effect of lozartan (5 mg/kg i.p.) on cerebral circulation and its autoregulation in hypertensive animals (a vasorenal model) in postischemic period. Transitory ischemia was induced by bilateral compression of the carotid arteries for 12 minutes, continued--by ligation of the carotid arteries. It was found that blockade of angiotensin receptors by lazartan provoked lowering of systemic arterial pressure. Changes in cerebral circulation were unstable, depended on arterial pressure and vascular cerebral resistance. The lower limit of autoregulation of the brain flow shifted to higher arterial pressure in hypertensive animals before brain ischemia and disorder after ischemia. Lozartan promoted recovery of the autoregulatory reactions of the brain vessels and raised survival of rats in continuous ligation of the carotid arteries.

[Brain ischemia induced by gravitational overload]. / Ishemiia golovnogo mozga, vyzvannaia gravitatsionnoi peregruzkoi.

It is suggested that radial gravitational overloads in craniocaudal direction, during which the pressure in meningeal arteries drops to zero, can be used to model the ischemic state. The post-ischemic period is characterized by increasing content of lipid peroxidation products in the venous blood and by violation of the neurological state in rats. This ischemia model, requiring no anaesthesia for the experimental animals, can be used in the directed search for new neuroprotectors and their characterization.

[Cerebrovascular circulation during blockade of angiotensin receptors]. / Mozgovoi krovotok v usloviiakh blokady angiotenzivnykh retseptorov.

In experiments on anaesthetized rats, Losartan was found to cause an obvious decrease in the ABP in normotensive rats. The cerebral blood flow differed independence on cerebral vascular resistance and the ABP level. The autoregulation of the cerebral blood flow remained unaltered. In hypertensive rats Losartan caused a significant decrease in the ABP as compared with normotensive rats. A shift of lower limits of the cerebral blood flow autoregulation towards a lower ABP level, was observed.

[The effect of captopril on cerebral blood flow in hypertensive rats before and after cerebral ischemia]. / Vliianie kaptoprila na mozgovoi krovotok u gipertenzivnykh krys do i posle ishemii mozga.

Acute experiments were conducted on narcotized hypertensive rats (vasorenal hypertension) to study the effect of captopril (5 mg/kg, intraperitoneal injection) on arterial pressure and cerebral blood flow and its autoregulation before and after transitory (10-12 min) ischemia of the brain (bilateral occlusion of the carotid arteries). Captopril normalized the arterial pressure, but changes in the cerebral blood flow proved to be insufficiently stable, particularly in the postischemic period. Normalization of autoregulation of the cerebral blood flow was noted. In captopril treatment the survival rate among rats with ischemia of the brain increased.

[The effect of captopril and enalapril on the cerebral circulation of normotensive rats]. / Vliianie kaptoprila i énalaprila na mozgovoe krovoobrashchenie normotenzivnykh krys.

Kaptopril and enalapril caused a stable decrease of arterial pressure and resistance of cerebral vessels in experiments on narcotized rats with artificial ventilation of the lungs. No significant changes occurred in the flow of blood in the brain because the drug under study potentiated autoregulatory reactions of the cerebral vessels in response to the decrease in arterial pressure.