Changes in endothelial cellular adhesion molecule mRNA expressions in the cerebral blood vessels of rats with prestroke condition caused by simulated cold wave / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the changes in the mRNA expression of endothelial cellular adhesion molecules in the cerebral blood vessels in rats with prestroke condition caused by simulated cold wave.</p><p><b>METHODS</b>Two-kidney two-clip renovascular hypertension was induced in 48 male SD rats, which were subsequently randomly assigned into cold wave exposure and non-exposed group (n=24). Each group was further divided into 4 sub-groups according to their systolic blood pressure, namely the sham-operated group with blood pressure (BP)<140 mmHg, mild hypertensive group with BP of 160-199 mmHg, moderate hypertensive group with BP of 200-219 mmHg, and severe hypertensive group with BP no less than 220 mmHg. Cold wave exposure was simulated by housing the rats in an artificial climate chamber with 3 cycles of 12 h light at 22 degrees celsius; and 12 h dark at 4 degrees celsius;. The non-exposed group was kept at 22 degrees celsius; throughout the experiment. After the exposure, the rats were sacrificed and the tissues of the frontal lobe were slice into 2.0-mm-thick coronal sections for real-time RT-PCR detection of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and p-selectin mRNA expressions. The 5.0-microm-thick frozen sections from the bregma section underwent in situ hybridization of VCAM-1, ICAM-1, and p-selectin. The other sections were stained with HE to observe the infarct lesions, and the rats with cerebral infraction were excluded from the statistical analysis.</p><p><b>RESULTS</b>In rats with cold wave exposure-induced prestroke condition and BP <220 mmHg, VCAM-1, ICAM-1, and p-selectin mRNA expressions all increased compared with those in the non-exposed group. In rats with BP>or=220 mmHg and cold exposure, the expressions all decreased to some extent compared with those in the non-exposed treatment. In the non-exposed rats, a positive correlation of BP to VCAM-1, ICAM-1, and p-selectin mRNA expressions were noted, and this correlation was also found in cold-wave-exposed rats with BP <220 mmHg; VCAM-1, ICAM-1, and p-selectin mRNA expressions decreased dramatically in the exposed rats with BP >or=220 mmHg compared with those in rats with BP <220 mmHg.</p><p><b>CONCLUSION</b>Persistent and severe hypertension impairs the modulatory function of the cerebral vascular endothelia, which is a prerequisite for the stroke vulnerability. The modulatory function deteriorates as the BP further increases.</p>

Cultured human embryonic neocortical cells survive and grow in infarcted cavities of adult rat brains and interconnect with host brain / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>There are no reports on exnografting cultured human fetal neocortical cells in this infracted cavities of adult rat brains. This study was undertaken to observe whether cultured human cortical neurons and astrocytes can survive and grow in the infarcted cavities of adult rat brains and whether they interconnect with host brains.</p><p><b>METHODS</b>The right middle cerebral artery was ligated distal to the striatal branches in 16 adult stroke-prone renovascular hypertensive rats. One week later, cultured cells from human embryonic cerebral cortexes were stereotaxically transferred to the infarcted cavity of 11 rats. The other 5 rats receiving sham transplants served as controls. For immunosuppression, all transplanted rats received intraperitoneal injection of cyclosporine A daily starting on the day of grafting. Immunohistochemistry for glial fibrillary acidic protein (GFAP), synaptophysin, neurofilament, and microtubule associated protein-2 (MAP-2) was performed on brain sections perfused in situ 8 weeks after transplantation.</p><p><b>RESULTS</b>Grafts in the infarcted cavities of 6 of 10 surviving rats consisted of bands of neurons with an immature appearance, bundles of fibers, and GFAP-immunopositive astrocytes, which were unevenly distributed. The grafts were rich in synaptophysin, neurofilament, and MAP2-positive neurons with long processes. The graft/host border was diffuse with dendrites apparently bridging over to the host brain, into which neurofilament immunopositive fibers protruded.</p><p><b>CONCLUSION</b>Cultured human fetal brain cells can survive and grow in the infarcted cavities of immunodepressed rats and integrate with the host brain.</p>

Experimental study on the therapeutic effectiveness of defibrase in rat focal cerebral ischemia reperfusion model / 中国康复理论与实践

@#ObjectiveTo investigate the therapeutic effectiveness of defibrase in treating penumbra and reperfusion.MethodsIntraluminal suture method was used to develope reversible middle cerebral artery occlusion(MCAO). Rats were subjected to MCAO 3 hours followed by reperfusion for 3, 6, 24, 72 hours, and to MCAO 6 hours followed by reperfusion for 3, 6, 24 hours. The treatment groups rats were injected intravenously defibrase at 0.5 hour before reperfusion. Meanwhile, the control group received normal saline. Clinically Neurological Deficits Scale were evaluated every day. Infarction volume was measured by using 2,3,5-triphenyltetrazolium chloride staining. Pathologic change were examined microscopically in HE stained sections.ResultsThere were significant difference at treatment groups of reperfusion 3 hours after MCAO.Infarction volume and Clinically Neurological Deficits Scale was significant reduced as control group (P<0.05). There were no significant differences at treatment groups of reperfusion 6 hours after MCAO (P>0.05). Cerebral hemorrhage wasn't increased in defibrase treatment group.ConclusionsDefibrase was effective on Clinically Neurological Deficits of rats in reperfusion 3 hours after MCAO.

Experimental studies on the protective effect of defibrase againstreperfusion injury after cerebral ischemia / 中国临床药理学与治疗学

Aim To ascertain whether defibrase has the protective effect against reperfusion injury after cerebral ischemia.Methods 70 renovascular hypertensive rats(RHR) were randomly divided into defibrase group, control group and sham-operated group.Reversible middle cerebral artery occlusion(MCAO) models were produced by the modified. Longa's method,and reperfusion was begun 2 hours after occlusion.Rats in the defibrase group were given defibrase 10 U?kg-1 body weight via femonal intraveneous injection, and in the control group with the same amount of saline. The brain pieces were processed by TTC and HE staining and the infarct size,brain microvessels damage and secondary bleeding were compared between the two groups. Results The volume of infarction in the defibrase group was obviously smaller than in the control group, the damage of brain microvessels was less severe, and the bleeding lesions under optical microscope were less than in the control group. Conclusion Defibrase has protective effect against reperfusion injury post cerebral ischemia.