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Objective To investigate changes in the number and function of endothelial progenitor cells (EPCs) in elderly patients with permanent atrial fibrillation(AF).Methods This prospective study included 35 elderly patients in each the permanent atrial fibrillation group and the control group.The numbers of circulating CD34+/KDR+ cells in the two groups were determined by flow cytometry.After two sets of peripheral blood samples were taken,mononuclear cells were isolated through density gradient centrifugation and cultured in vitro.EPC colonies were identified by the methylthiazolyldipheny-tetrazolium(MTT) assay and adhesion assay.The proliferation,adhesion and vasculogenesis of EPC colonies were determined by Matrigel culture.Enzyme-linked immunosorbent assay and nitric acid reductase assay were used to measure the secretion of vascular endothelial growth factor (VEGF) and nitric oxide (NO) in EPCs.Results The numbers of CD34+/KDR+ cells were lower in the AF group than in the control group (20.0±12.7)/104 vs.(77.9±58.9)/104 (P＜0.05).The number of EPC colonies in the atrial fibrillation group was significantly lower than that in the control group (1.8 ± 0.6) CFU vs.(3.5 ± 0.8) CFU (P ＜ 0.01).The proliferation,adhesion and vasculogenesis of EPC colonies in the AF group decreased,compared with the control group (each P＜0.01 or 0.05).Paracrine secretion of VEGF in the AF group (27.4±9.9)ng/L was lower than that in the control group (41.9±7.3)ng/L (P＜0.01) and paracrine production of NO in the AF group also decreased (P＜0.05).Conclusions EPCs In elderly patients with permanent atrial fibrillation show decreased numbers and reduced proliferation,adhesion and vasculogenesis.Paracrine VEGF and NO secretion is down as well.
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Objective To investigate the effect of lumbar subarachnoid space continuous drainage on cerebral vasospasm(CVS) prevention and treatment following experimental subarachnoid hemorrhage(SAH), and further explore the mechanism of CVS prevention and treatment.Methods An experimental SAH was achieved by twice injections of fresh autologous arterial blood into cisterna magna of each dog. The dogs were randomly divided into drainage group and control group and it was just after the second injection of fresh blood that the drainage group began to drain blood cerebral spinal fluid(CSF).The contents of red blood cell(RBC), endothelin-1(ET-1) and nitric oxygen(NO) in CSF were measured respectively. The degree of CVS was analyzed through angiography (%reduction of basilar artery diamiter,%RBAD). The angiographic results of CVS were analyzed and the changes of RBC, ET-1 and NO in CSF at different stages were compared between two groups. Results The drainage group had fewer cases of CVS and the severity of CVS was more slight compared with control group.Drainage group had a significantly higher cleaning rate of RBC.In drainage group,the content of ET-1 was lower and the content of NO was higher significantly than control group.Conclusions Through cleaning the vasogenic substances in subarachnoid space,lumbar subarachnoid space continuous drainage can change the levels of ET-1 and NO in CSF and may prevent and reverse CVS following.
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Objective To investigate the relationship between endothelin-1(ET-1)and NO in cerebral spinal fluid(CSF) and cerebral vasospasm(CVS) following experimental subarachnoid hemorrhage(SAH).Methods An experimental CVS model was achieved by twice injections of fresh autologous arterial blood into the cisterna magna of each animal. The contents of ET-1 and NO in CSF were measured by radioimmunological analysis and activated cadmium reduction method respectively.The degrees of CVS were analyzed through cerebral angiography(%reduction of basilar artery diamiter,%RBAD). Results The contents of ET-1 in CSF increased significantly than that before injection after SAH(P
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Oxygen-derived free radicals have been implicated in many important functions in the biological system. Electrical field stimulation (EFS) causes arterial relaxation in animal models. We found that EFS applied to neither muscle nor nerve but to Krebs solution caused a relaxation of rat aorta that had been contracted with phenylephrine. In the present study, therefore, we investigated the characteristics of this EIRF (electrolysis-induced relaxing factor) using rat isolated aorta. Results indicated that EIRF acts irrespective of the presence of endothelium. EIRF shows positive Griess reaction and is diffusible and quite stable. EIRF-induced relaxation was stronger on PE-contracted aorta than on KCl-contracted one, and inhibited by the pretreatment with methylene blue. Zaprinast, a cGMP-specific phosphodiesterase inhibitor, potentiated the EIRF-induced relaxation. NG-nitro-L-arginine, NO synthase inhibitor, did not inhibit the EIRF-induced relaxation. Deferroxamine, but not ascorbic acid, DMSO potentiated the EIRF-induced relaxation. These results indicate that electrolysis of Krebs solution produces a factor that relaxes vascular smooth muscle via cGMP-mediated mechanism.