RESUMO
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 groups:an 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.
RESUMO
The types of the voltage-dependent calcium channels (VDCCs) in human ejaculatory sperm and the effects of calcium channel blocker (CCB) on human sperm motility parameters in vitro were investigated. The human sperm motility parameters in vitro in response to the pharmacological agents nifedipine (NIF, inhibitor of L-type VDCC) and ω-conotoxin (GVIA, inhibitor of N-type VDCC) were compared and analyzed statistically. The results showed that NIF (1, 5, 10 μmol/L)could not only significantly affect human sperm's shape but also spermatozoa motility after incubated at least 10 min in vitro (P＜0.001). GVIA (0.1, 0.5 and 1 μmol/L) could just only significantly affect human sperm's progressive motility (a %+b %) after incubated for 20 min in vitro (P＜0.01), but they both could not significantly affect spermic abnormality rate. It is suggested that L-type VDCC, non L-type VDCCs and isoform of L-type VDCC exist in the cell membrane of human sperm solely or together, and they participate in the spermic physiological processes especially the spermic motility.