| ObjectiveSubarachnoid hemorrhage(SAH) is a clinical syndrome that caused by intracranial and spinal vascular various sudden rupturing, blood flowing to the subarachnoid space, which accounting for 10.0% of acute stroke. It is a neurological diseases of high mortality and high morbidity. Cerebral vasospasm (CVS) is specific complications of SAH, which is secondary to the cerebral blood flow decline, it is the main risk factors for death and disability. The annual rate of SAH is about 1/1 million, and its responsibilities vascular can be divided into arteries and veins. The former accounts for about 85% of SAH, that mostly is aneurysm, vascular malformation and tumors caused by stroke; the latter mostly is primary disease or intracranial venous sinus thrombosis, blood coagulation disorders and brain around non-aneurysmal of SAH and so on. Venous SAH have mild symptoms, a low incidence of cerebral vasospasm and great prognosis. Since the composition of arterial and venous is different, we observed the sensitivity to cerebral vasospasm and the regulation of blood components to the voltage-dependent calcium channels current (VDCCs) between arterial and venous, to find differences of arterial and venous SAH in VDCCs current, resting potential and cerebral blood flow (CBF), in order to provide better basis for the treatment of SAH.MethodChoosing 36 SD rats (male or female) and divided into arterial SAH group (N= 14 rats), venous SAH group (N= 13 rats) and sham operation group (N= 9) according to figures random sampling method. Using rats stereotactic apparatus to make SAH models. SAH groups were injected 0.25 ml autologous blood into supra sella cistern, the sham group was rinjected an equivalent amount of hypertonic saline in the same manner. Evaluating nerve function score after 3d, the rats were sacrificed and the brain was weighed, using fluorescence spectrophotometer to test solution and calculate the absolute value of cerebral blood flow. Isolated cerebral arteries under the microscope, then move the the cerebral arteries to glutamate solution through gentle pipetting approximately 1 min to make smooth muscle cells separate. The isolated cell suspensions was quickly placed under an inverted microscope for cell count in high-power field, to determine the cell membrane integrity and survival rate of cells. Dropping Arterial smooth muscle cell suspension into the microscope recording bath to measure the resting potential. Using patch clamp to study the cerebral arterial smooth muscle cells relative surface area and VDCCs current.ResultsWhen injected Saddle autologous arterial blood, venous blood and saline, three groups of rats present different mental state. The indicators of arterial SAH group (N=14), venous SAH group (N=13) and sham group (N=9) have some differences after postoperation.1. The OxyHb concentration of arterial SAH, venous SAH and sham group is different. The OxyHb concentration of arterial SAH was significantly higher than SAH group, sham group (P<0.05).2. The neural function score of all rats was 18 points. The neural function score of arterial SAH, venous SAH and sham group is different after 3 d. Arterial SAH and venous SAH group was lower than sham group (P<0.05).3. Under high power field, the cerebral artery smooth muscle cells living cell ratio (%) of arterial SAH, venous SAH and sham group SAH has no difference.4. The relative surface area of cerebral arterial smooth muscle cells of arterial SAH, venous SAH and sham group is different. The relative surface area of cerebral arterial smooth muscle cells of arterial SAH is significantly less than venous SAH, sham group (P<0.05).5. The cerebral arterial smooth muscle cell resting potential of arterial SAH, venous SAH and sham group is different. The cerebral arterial smooth muscle cell resting potential of arterial SAH was significantly lower than venous SAH, sham group (P<0.05).6. The VDCCs currents(pA) of arterial SAH, venous SAH and sham groups is different. When Vm= 0-30 mV, the VDCCs current density of arterial SAH is significantly higher than venous SAH, sham group (P<0.05).7. The cerebral blood flow of arterial SAH, venous SAH and sham group is different. The cerebral blood flow of arterial SAH was significantly lower than venous SAH, sham group (P<0.05).Conclusion1. This study shows that compared with the VDCCs currents of normal cerebral artery smooth muscle cells, the arterial SAH can make cerebral arterial smooth muscle cells VDCCs current density increase and current subtype change, while making CBF significantly decrease; venous SAH had no such effect. 2. This study shows that these differences were likely related to the different components of the arterial and venous blood, especially to factors leading to vasospasm such as the concentration of oxyhemoglobin. |
PDF Full Text Request