The Experimental Study of Stress-Related Pathological Changes in Cerebral Venous Blood Flow in Newborn Rats Assessed by Doct

Abstract

In experiments on newborn rats with stress-related intracranial hemorrhage (ICH) using Doppler optical coherence tomography (DOCT) we have shown that latent stage of ICH (4 h after stress) is characterized by decrease of venous blood out°ow and the loss of sensitivity of sagittal vein to vasoconstrictor e®ect of adrenaline. The incidence of ICH (24 h after stress) was accompanied by progression of early pathological changes in cerebral venous blood°ow (CVBF) and development of venous insu±ciency. Taking into consideration of this fact, we suggest that the suppression of CVBF related to the severity to the deleterious e®ect of stress on the brain hemodynamics in newborn rats. These facts allow us to conclude that the venous insu±ciency with the loss of vasoconstrictor response to adrenaline is an informative and sensitive component of pattern of CVBF that can be important diagnostic criteria of risk of ICH development in newborns.

Blood-brain barrier and cerebral blood flow: Age differences in hemorrhagic stroke

“…25 Adrenaline caused vasoconstriction of cerebral vessels in healthy rats but did not induce any changes in the CBF in rats with intracranial hemorrhages, probably due to decrease in the BBB permeability. 13 Here, we proposed adrenaline test as additional indirect method to the study of BBB permeability as well as to determine e®ectiveness of adrenaline as a main course in therapy of stroke [27][28][29] in neonates and adults.…”

“…[1][2][3] The cerebral venous disturbances are one of the important mechanism underlying pathological changes in the CBF associated with the stroke. [23][24][25] It is also known that neonatal stroke is primary the venous infarction 30,31 due to a weakness in the wall of cerebral veins in neonates. 32 Taking into account of these facts, we analyzed the changes in hemodynamic parameters of the sagittal sinus as a main venous sinus of the brain collecting blood from the all cerebral veins.…”

“…[22][23][24][25] This procedure was performed in the Plexiglas chamber (the volume is 2000 sm 3 ) absorbing and amplifying of deleterious e®ects of sound on the rats.…”

Hidden stage of intracranial hemorrhage in newborn rats studied with laser speckle contrast imaging and wavelets

“…Section 4 contains some concluding remarks. A previously described model of a severe stress 18,19 was applied to induce the ICH in newborn rats. The animals were placed in the Plexiglas chamber (volume -2000 cm 3 ) and underwent intermittent infra-sound (10 Hz, 120 dB) that repeated during 2 h (10 s -the sound, 60 s -the interruption).…”

“…The appearance of ICH during the next day after such stress was veri¯ed by magnetic resonance imaging and histological studies. 18 Three groups of newborn rats were selected for further analysis of CVBF: a control group (unstressed rats, n ¼ 19), stressed rats with the hidden stage of ICH (4 h after the stress-o®, n ¼ 18), and stressed rats with ICH (24 h after the stress-o®, n ¼ 22).…”