血管活性肽对同型半胱氨酸刺激平滑肌细胞增殖的实验研究

Influence of vasoactive peptides on homocysteine induced proliferation of cultured rabbit vascular smooth muscle cell

目的观察对兔主动脉平滑肌细胞（ＶＳＭＣ）增殖起负调节作用的Ｃ型利钠利尿肽（ＣＮＰ）、肾上腺髓质素（Ａｄｍ）、降钙素基因相关肽（ＣＧＲＰ）、生长抑素（ＳＳＴ）和甲状旁腺素相关蛋白（ＰＴＨｒＰ）等活性肽对同型半胱氨酸（Ｈｃｙ）刺激的ＶＳＭＣ增殖的影响。方法６只大耳白兔胸主动脉贴块法离体培养平滑肌细胞；分对照及Ｈｃｙ加不同处理因素组；３ＨＴｄＲ掺入测定ＶＳＭＣ增殖；差速离心分离细胞膜、胞浆及胞核并分别测定细胞膜、胞浆及胞核的蛋白激酶Ｃ（ＰＫＣ）活性。结果Ｈｃｙ可显著刺激平滑肌细胞增殖，１０－４ｍｏｌ／ＬＨｃｙ使ＶＳＭＣ３ＨＴｄＲ掺入较对照组增加１．８倍。单用Ａｄｍ、ＣＮＰ、ＣＧＲＰ、ＳＳＴ和ＰＴＨｒＰ对３ＨＴｄＲ掺入无显著影响，但可呈剂量依赖的抑制Ｈｃｙ诱导的平滑肌细胞ＤＮＡ合成。蛋白激酶Ｃ活性抑制剂Ｈ７和Ｓｔａｕｒｏｓｐｏｒｉｎｅ显著抑制Ｈｃｙ诱导的ＶＳＭＣ的增殖，分别使ＶＳＭＣ３ＨＴｄＲ掺入下降５０％（Ｐ＜０．０１）和５６％（Ｐ＜０．０１）。１０－４ｍｏｌ／ＬＨｃｙ使ＶＳＭＣ总ＰＫＣ活性较对照组增加４０％（Ｐ＜０．０１），其中细胞膜和细胞核活性分别增加２００％（Ｐ＜０．０１）和５７％（Ｐ＜０．０１）?

Abstract Objective To study the effects of vasoactive peptides adrenomedullin(Adm), C type natriuretic peptide (CNP), calcitonin gene related peptide (CGRP), somatostatin(SST) and parathyroid homone related protein] on homocysteine(Hcy) induced proliferation of cultured rabbit vascular smooth muscle cell (VSMC). Methods Techniques of cell culture, 3 H thymidine incorporation, nuclei, membrane and cytosol fractions were isolated by differential centrifugation and PKC activity was measured. Results Hcy significantly stimulated DNA synthesis of VSMC. Adm、 CNP、 CGRP、 SST、 and PTHrP had no effect on basal 3 H TdR incorporation, but they could inhibit Hcy induced 3 H TdR incorporation in dose dependent manner. PKC inhibitor (H 7 and Stauroporine )could inhibit VSMC proliferation induced by Hcy with reduction of 3 H TdR incorporraion by 50% and 56% ,respectively.PKC was found to be distributed equally in nuclear fraction and membrane particulate,and higher in cytosol fraction in untreated VSMC. Treatment of VSMC with 10 mol/L Hcy resulted in a significant increase in membrane associated PKC combined with a loss of enzyme activity in the cytosol and nuclear fractions.Adm,CNP ,CGRP and PTHrP altered the distribution of PKC activity induced by Hcy. Conclusion Adm,CNP ,CGRP and PTHrP inhibited VSMC proliferation possibly through PKC pathway. Adrenomedublin