神经肽Y刺激肾动脉平滑肌热休克蛋白表达及Losartan的干预作用

目的　探讨以HSP70作为神经肽Y (NPY)和losartan间在肾动脉血管平滑肌细胞(VSMC)增殖活动相互作用为信号 ,在高血压肾动脉重塑中的作用。方法　应用快速微量MTT比色法和荧光免疫组织化学定量技术 ,观察神经肽Y作用下肾动脉VSMC增殖活动中热休克蛋白 (heatHSP)表达以及Losartan对NPY作用的干预作用。结果　神经肽Y刺激体外培养肾动脉平滑肌细胞的增殖度 (吸光度A值为 0 2 6 2 6± 0 0 0 2 5 )与细胞内因损伤产生的HSP70表达 (A值为 0 2 44 0±0 0 0 13)明显高于对照组 (A值为 0 2 2 3 9± 0 0 0 10 ) (P <0 0 1)。losartan可降低NPY对肾动脉平滑肌细胞的增殖度 (A值 )的刺激作用 ,减少细胞内HSP70的表达。结论　神经肽Y可影响肾动脉平滑肌细胞增殖引起高血压 ,而HSP70表达水平是肾动脉平滑肌细胞增殖的重要信号。

Stimulation of neuropeptide Y on heat shock protein expression in renal vascular smooth muscle and the inhibition thereon by losartan

OBJECTIVE: To study the effect of neuropeptide Y (NPY) on the expression of heat shock protein 70 (HSP70) in vascular smooth muscle cells (VSMCs) of renal arteries. METHODS: The renal veins of SD rats were isolated and broken into pieces. The VSMCs were cultured and then divided into 3 groups, neuropeptide Y (NPY), NPY + losartan, and serum-free DMEM were added into the culture respectively. Automated MTT colorimetric microassay and quantitative immunocytochemistry were used to detect the expression of heat shock protein (HSP70) in the proliferating VSMCs. RESULTS: The fluorescence intensity of labeled HPS70 in the NPY group was 1,825.10 +/- 115.55, significantly stronger than that in the control group (1595.83 +/- 186.54, P < 0.05) and the fluorescence intensity of labeled HPS70 in the NPY + losartan group (1 658.54 +/- 183.78) was not significantly different from that in the control group (P > 0.05). The MTT-OD in NPY group was 0.2626 +/- 0.0025, significantly higher than that in the control group (0.2239 +/- 0.0010, P < 0.01). and the MTT-OD in NPY + losartan group was 0.2440 +/- 0.0013, significantly lower than that in the control group (P < 0.05). CONCLUSION: NPY stimulates the proliferation of renal VSMC, promotes the expression of HPS70, and may cause hypertension. Losartan reduces the NPY stimulation over VSMC proliferation and relevant expression of intracellular HSP70.