[Effects of yinian jiangya decoction contained serum on endothelial cell proliferation and PPAR gamma mRNA expression in spontaneously hypertensive rat].

OBJECTIVE

To observe the effects of Yinian Jiangya (YNJY) Decoction contained serum on cell proliferation of primary cultured endothelial cells of spontaneously hypertensive rat (SHR) and the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) mRNA expression in the cells.

METHODS

SD rats were fed with high-lipid diet and different doses (high, medium and low, containing crude drug of 5.2 g/mL, 2.6 g/mL, 1.3 g/mL respectively) of YNJY respectively and the serum contained different doses of YNJY (S-YNJY) was prepared by collecting the rats' serum after 20 days of feeding. The serum obtained from SD rats fed with normal diet, i.e. drug free serum (S-free) was taken for control. Primary cultured endothelial cells of SHR were treated respectively with S-YNJY in different doses (treated groups) and S-free (control group), the cell activity and the mRNA expression of PPAR-gamma in cells of all groups were detected by MTT and RT-PCR respectively at different time points: 2, 4, 8, 16 and 24 h after treatment.

RESULTS

MTT test showed that at time points of 4 and 8 h, the OD value raised in the treated groups with insignificant difference among them (P>0.05), but was higher than that in the control group (P<0.05); at 16 h, it increased but showed a smaller increment in the medium-dose treated group (P<0.05); at 24 h, it decreased in all groups, but the decrement in the high- and medium-dose treated groups was more remarkable (P<0.05); at 48 h, it decreased continuously, with the decrement more significant in the high-dose group than in the control group (P<0.05). RT-PCR detection showed that at 4 h, the expression of PPAR-gamma mRNA was not changed significantly in all groups (P>0.05); at 8 h, it was remarkably lower in high-dose group than in others (P<0.05); at 16 h, it was higher in the three treated groups than in the control group (P<0.05), with a highest level shown in the high-dose treated group (P<0.01); at 24 h, the expression decreased in all groups, but the level in the low-dose treated group was still higher than that in the control group (P<0.05).

CONCLUSIONS

YNJY Decoction shows a two-way regulation on endothelial cells proliferation, and which is negatively dose-dependent in the late stage. The regulation is perhaps relevant to the regulating of the PPAR-gamma mRNA expressions. The PPAR-gamma mRNA expression up-regulating and maintaining effects of YNJY Decoction may be one of the mechanisms for its vascular endothelial cell protection and blood pressure suppressing.