[Effects of DDPH on proliferation and immunophenotypes of the pulmonary vascular pericytes]

To study the effects of 1-(2, 6-dimethylphenoxy)-2-(3, 4-dimethoxyphenylethylamino) propane hydrochloride (DDPH) on proliferation and immunophenotypes of newborn rat pulmonary vascular pericytes (PCs) induced by hypoxic endothelial cell conditioned medium (HECCM) from porcine pulmonary arteries.

The PCs were divided into 4 groups according to the endothelial cell conditioned medium (ECCM): normoxic ECCM (NECCM) group, NECCM + DDPH group, HECCM group and HECCM + DDPH group. Cell culture, immunocytochemical staining, image analysis and flow cytometry were used to investigate the effects of HECCM and DDPH on the expression of alpha-smooth muscle actin (alpha-SM-actin) and proliferating cell nuclear antigen (PCNA) and cell cycle in PCs.

The alpha-SM-actin antigen in the PCs in HECCM group was more positively expressed than that in the other three groups, but CD(34) antigen and S-100 antigen were negatively expressed. The expression of alpha-SM-actin antigen, CD(34) and S-100 was positive in the groups of NECCM, NECCM + DDPH and HECCM + DDPH. The expression of alpha-SM-actin and PCNA in HECCM group was 1.32 times (F = 11.09, P = 0.000 1) and 1.24 times (F = 2.89, P = 0.025 7) that in NECCM group, 1.30 times (F = 3.65, P = 0.007 0) and 1.21 times (F = 2.63, P = 0.041 4) that in HECCM + DDPH group, respectively; The percentage of the cells in the G(0)-G(1) phase in the HECCM group was lower by 11.7% and 9.1%, in S phase higher by 5.6% and 4.2%, in G(2)-M phase higher by 6.1% and 4.9% than that in the groups of NECCM, HECCM + DDPH, respectively. The inhibitory rates of DDPH on the increased alpha-SM-actin and PCNA syntheses in PCs induced by HECCM were 23.4% and 17.1% respectively. The inhibitory rate on the increased PCs from G(0)-G(1) phase to S phase was 8.3%.

DDPH might directly inhibit PCs from proliferation and immunophenotypical transformation of smooth muscle-like cells induced by HECCM.