Influence Of Calcitonin Gene-related Peptide On The Proliferation Of Vascular Smooth Muscle Cells

Objective To evaluate the effect of neuropeptide on the proliferation and migration of vascular smooth muscle cells(VSMCs), this study was to investigate whether calcitonin gene-related peptide(CGRP) can regulate the proliferation and migration of vascular smooth muscle cells reduced by diamide. Methods VSMCs of abdominal aorta were obtained fresh aborted 5-month human fetus through primary culture.The purity of cultured VSMCs was assessed by positive immuoreaction cells of anti-α-smooth-actin with immunocytochemical method.The experiment was divided into four groups:A,diamide group, B,CGRP group,C,diamide and CGRP group,D,control group. the concentration of CGRP and Diamide is 2×10^-7M and 5×10^-6M respectively. the proliferous change of VSMCs was confirmed by the MTT and cell counter method. The mRNA expression change of the cyclin D1 and the tissue inhibitor of metalloproteinase-2(TIMP-2) was detected by reverse transcription-polymerase chain raction method (RT-PCR) and the changes of the cell cycle .by flow cytometry . Results It was shown that the primary cultured VSMCs grow like a peak and valley appearance and the purity of primary cultured VSMCs was 98 %. From the curve of growth of VSMCs, it can be seen that the logarithmic growth phase of the VSMCs was in 3 to 5 day after beginning.The diamide can increase VSMCs proliferation by lipid peroxidation.CGRP can increase the VSMCs'proliferation at the beginning,but after 24h the proliferous VSMCs were inhibited by CGRP. Nevertheless,CGRP intensive inhibitory effect on the proliferous VSMCs induced by diamide. CGRP can down regulate the mRNA expression of cyclin D1 and up regulate the expression of tissue inhibitor of metalloproteinase-2.It is suggested that CGRP can regulate the proliferation and migration of VSMCs. Conclusion 1. the purity of primary culture of VSMCs obtained from fresh aborted 5-month human abdominal aorta was 98%.2.The diamide can induce the VSMCs proliferation. 3.CGRP can down regulate the proliferation of VSMCs induced by diamide . It is showed that CGRP might have regulative effect on the proliferation of VSMCs, but the mechanism need to study further . 4. CGRP can up regulate the mRNA expression of tissue inhibitor of metalloproteinase-2. 5.The reserch of CGRP's effect on the proliferation of VSMCs is very important,which might be significant in the development of atherosclerosis.