Effect of arterial and venous subarachnoid hemorrhage on voltage-dependent calcium channel currents of cerebral artery smooth muscle cells in rats / 中国脑血管病杂志

ABSTRACT

Objective To investigate the effect of arterial and venous subarachnoid hemorrhage ( SAH)on voltage-dependent calcium channel( VDCC)currents of cerebral artery smooth muscle cells and the relationship between the concentration of oxyhemoglobin( OxyHb)in arterial and venous blood and cerebral blood flow. Methods Thirty-six clean grade rats were colleted. A rat SAH model was induced by injection of autologous arterial or venous blood in suprasellar cistern using assisted stereotaxic apparatus. The rats were divided into three groupsan arterial SAH( n=14 ),a venous SAH( n=13 ),and a sham operation( n=9 )group. The arterial and venous OxyHb concentrations were measured. Three days after SAH modeling,a patch clamp was used to detect the relative surface area of the cerebral artery smooth muscle cells,resting potential,and VDCC currents in rats. A fluorescent microsphere method was used to quantitatively analyze cerebral blood flow(CBF). Results (1)Arterial SAH OxyHb concentration (127 ± 4 g/L)was significantly higher than venous SAH OxyHb concentration(54 ± 6 g/L),and that of the sham operation group was 50 ± 5 g/L. The differences were statistically significant among the 3 groups( P<0. 01).(2)The maximum current of VDCC of the arterial SAH group(3. 22 ± 0. 31 pA)was significantly higher than that of the venous SAH group(2. 19 ± 0. 27 pA)and the sham operation group(2. 18 ± 0. 29 pA). The differences were statistically significant among the 3 groups( P<0. 01 ). The VDCC currents of the arterial SAH group were consisted of L- and R-currents,while the currents of the venous SAH group were only consisted of L-VDCC.(3)The cerebral blood flow of the arterial SAH group(0. 83 ± 0. 14 mL/[g·min])was significantly higher than that of the venous SAH group(1. 28 ± 0. 28 mL/[g·min])and the sham operation group(1. 35 ± 0. 19 mL/[g·min]). The differences were statistically significant(P<0. 01). Conclusions The changing effect of arterial SAH on the expression and function of the cerebral artery smooth muscle cells are greater than that of the venous SAH. This difference may be associated with the concentration and composition of vasospasm factors of OxyHb in arterial and venous blood.