Objective.To investigate the effects of several vasoactive peptides on the development of arterial restenosis after balloon angioplasty. Methods. In rat aortic artery restenosis model produced by denudation of aortic ...Objective.To investigate the effects of several vasoactive peptides on the development of arterial restenosis after balloon angioplasty. Methods. In rat aortic artery restenosis model produced by denudation of aortic endothelia,we observed changes of endothelin(ET),angiotensin II(AII),calcitonin gene-related peptide(CGRP)and adrenomedullin(Adm)in plasma and aorta with radioimmunoassay and expression of hypertension-related gene(HRG-1)with semi-quantitative RT-PCR,and studied the effects of these peptides on intimal hyperplasia,intima/media ratio and MAPK activities of aortic artery after angioplasty respectively. Furthermore,in cultured cells,we studied the effects of these peptides on vascular smooth muscle cell(VSMC) proliferation and expression of HRG-1 of VSMC from spontaneously hypertensive rats(SHR)and Wistar-Kyoto(WKY)rats with 3H-TdR incorporation and RT-PCR respectively. Results. After angioplasty,the levels of ET and AII in plasma and aorta significantly increased,accompanied with VSMC proliferation and neointima hyperplasia. On day 10 after angioplasty,the levels of ET in plasma and aorta increased by 69% and 124% respectively,compared with sham group(P<0.01);and the level of aortic AII increased by 80%(P< 0.01). Antiserum against ET or inhibitors of angiotensin converting enzyme(ACE)could significantly inhibit the proliferation of VSMC and neointima formation. Compared with the sham group,on day 3 after angioplasty,the CGRP levels in plasma and aorta increased by 64% and 89% respectively(P< 0.01)and the Adm levels in plasma and tissue increased by 129% and 102% respectively(P< 0.01). On day 10,intravenous administration of CGRP significantly inhibited the proliferation of VSMC and neointima forma-tion induced by balloon aortic injury(by 66% and 79% respectively,P< 0.01). In addition,ET and AII attenuated the expression of HRG-1 in aorta and stimulated mitogen-activated protein kinase(MAPK)activity,while CGRP and Adm potentiated the expression of HRG-1 and inhibited MAPK.Conclusions. ET and AII can stimulate the proliferation of injured intima while CGRP and Adm have an anti-hyperplasia effect after angioplasty. These 4 peptides are involved in the regulation of VSMC proliferation and affect the development of vascular restenosis by regulating the expression of HRG-1 and MAPK activity.展开更多
A new spinning method to manufacture the cylindrical parts with nano/ultrafine grained structures is proposed, which consists of quenching, power spinning and recrystallization annealing. The microstructural evolution...A new spinning method to manufacture the cylindrical parts with nano/ultrafine grained structures is proposed, which consists of quenching, power spinning and recrystallization annealing. The microstructural evolution during the different process stages and macroforming quality of the spun parts made of ASTM 1020 steel are investigated. The results show that the microstructures of the ferrites and pearlites in the ASTM 1020 steel are transformed to the lath martensites after quenching. The martensite laths obtained by quenching are refined to 87 nm and a small amount of nanoscale deformation twins with an average thickness of 20 nm is generated after performing a 3-pass stagger spinning with 55% thinning ratio of wall thickness, where the equivalent strain required is only 0.92. The equiaxial ferritic grains with an average size of 160 nm and nano-carbides are generated by subsequent recrystallization annealing at 480°C for 30 min. The spun parts with high dimensional precision and low surface roughness are obtained by the forming method developed in this work, combining quenching with 3-pass stagger spinning and recrystallization annealing.展开更多
基金This work was supported by the research grants from the National Natural Sciences Foundation of China (39870355).This work was originally published in National Medical Journal of China(2001 18: 162-167)in Chinese.
文摘Objective.To investigate the effects of several vasoactive peptides on the development of arterial restenosis after balloon angioplasty. Methods. In rat aortic artery restenosis model produced by denudation of aortic endothelia,we observed changes of endothelin(ET),angiotensin II(AII),calcitonin gene-related peptide(CGRP)and adrenomedullin(Adm)in plasma and aorta with radioimmunoassay and expression of hypertension-related gene(HRG-1)with semi-quantitative RT-PCR,and studied the effects of these peptides on intimal hyperplasia,intima/media ratio and MAPK activities of aortic artery after angioplasty respectively. Furthermore,in cultured cells,we studied the effects of these peptides on vascular smooth muscle cell(VSMC) proliferation and expression of HRG-1 of VSMC from spontaneously hypertensive rats(SHR)and Wistar-Kyoto(WKY)rats with 3H-TdR incorporation and RT-PCR respectively. Results. After angioplasty,the levels of ET and AII in plasma and aorta significantly increased,accompanied with VSMC proliferation and neointima hyperplasia. On day 10 after angioplasty,the levels of ET in plasma and aorta increased by 69% and 124% respectively,compared with sham group(P<0.01);and the level of aortic AII increased by 80%(P< 0.01). Antiserum against ET or inhibitors of angiotensin converting enzyme(ACE)could significantly inhibit the proliferation of VSMC and neointima formation. Compared with the sham group,on day 3 after angioplasty,the CGRP levels in plasma and aorta increased by 64% and 89% respectively(P< 0.01)and the Adm levels in plasma and tissue increased by 129% and 102% respectively(P< 0.01). On day 10,intravenous administration of CGRP significantly inhibited the proliferation of VSMC and neointima forma-tion induced by balloon aortic injury(by 66% and 79% respectively,P< 0.01). In addition,ET and AII attenuated the expression of HRG-1 in aorta and stimulated mitogen-activated protein kinase(MAPK)activity,while CGRP and Adm potentiated the expression of HRG-1 and inhibited MAPK.Conclusions. ET and AII can stimulate the proliferation of injured intima while CGRP and Adm have an anti-hyperplasia effect after angioplasty. These 4 peptides are involved in the regulation of VSMC proliferation and affect the development of vascular restenosis by regulating the expression of HRG-1 and MAPK activity.
基金supported by National Natural Science Foundation of China(Grant No.51075153)Natural Science Foundation of Guangdong Province(Grant No.10151040301000000)+1 种基金Key Laboratory of Precision Equipment and Manufacturing Technology of Guangdong Province(Grant No.PEMT1202)the EU FP7 Marie Curie International Research Staff Exchange Scheme(IRSES)Mat Pro Future Project(Grant No.318968)
文摘A new spinning method to manufacture the cylindrical parts with nano/ultrafine grained structures is proposed, which consists of quenching, power spinning and recrystallization annealing. The microstructural evolution during the different process stages and macroforming quality of the spun parts made of ASTM 1020 steel are investigated. The results show that the microstructures of the ferrites and pearlites in the ASTM 1020 steel are transformed to the lath martensites after quenching. The martensite laths obtained by quenching are refined to 87 nm and a small amount of nanoscale deformation twins with an average thickness of 20 nm is generated after performing a 3-pass stagger spinning with 55% thinning ratio of wall thickness, where the equivalent strain required is only 0.92. The equiaxial ferritic grains with an average size of 160 nm and nano-carbides are generated by subsequent recrystallization annealing at 480°C for 30 min. The spun parts with high dimensional precision and low surface roughness are obtained by the forming method developed in this work, combining quenching with 3-pass stagger spinning and recrystallization annealing.
