Aim:The aim of the present study was to understand the role of retinoic acid (RA) in the development of isolated patent ductus arteriosus and the features of arterial duct-derived vascular smooth muscle cells (VSMC). Methods:The VSMC were isolated, and the biological characteristics and the response to RA were investi-gated in the arterial duct, aorta, and pulmonary artery VSMC from 6 human embry-onic samples. Weste blotting, immunostaining, and cell-based ELISA were em-ployed to analyze the proliferation regulation of VSMC. Results:The VSMC from the arterial duct expressed proliferating cell nuclear antigen (PCNA) at a signifi-cantly lower rate than those from the aorta and pulmonary artery, but expressed a higher level of Bax and Bcl-2. The expression level of PCNA or Bcl-2 was associ-ated with the embryonic age. The effects of RA on the VSMC from the arterial duct were quite different from those from the aorta and pulmonary artery. In arterial duct VSMC, RA stimulated PCNA expression, but such stimulation could be sup-pressed by CD2366, an antagonist of nuclear retinoid receptor activation. In aorta or pulmonary artery VSMC, the expression response of PCNA to RA was insignificant. The ratio of Bax/Bcl-2 decreased in arterial duct VSMC after RA treatment due to the significant inhibition of Bax expression. Conclusion:The VSMC from the arterial duct possessed distinct biological behaviors. RA might be important in the development of ductus arteriosus VSMC.