Influence of antioxidants on the contractile response of heat-stressed human umbilical artery smooth muscle cells

Objective To study the change of the contractile response of human umbilical artery smooth muscle cells (HUASMCs) during the heat stress, and explore the effect of the antioxidant on the changes. Methods HUASMCs were randomly divided into control group, heat stress group, antioxidant preprocessing group. Cells were stimulated by norepinephrine (NE) at a low concentration (0.05mg/L) and at a normal concentration (1.0mg/L) and cultured in the thermostatic water bath (41℃) for 0.5, 1, 1.5 or 2h, respectively. After stimulated by NE, proportion of the cell surface area contraction was measured to reflect the contractile response of each group. Results Compared with control group, regardless of the NE concentration: in heat stress group, contractile response at 1h increased significantly (P 0.05), but in the antioxidant preprocessing group, the contractile response was more significant to the normal NE concentration than to the low NE concentration (P<0.05 or 0.01). Regardless of the NE concentration, the contractile response was lower in the antioxidant preprocessing group than in the heat stress group. Conclusions In the course of heat stress, the contractile response of HUASMCs presents as time- related change. The usage of antioxidant may correct the over-response of HUASMCs to NE in the early heat stress stage, but cannot correct the reduction of the contractile response in the middle and advanced stage. DOI: 10.11855/j.issn.0577-7402.2017.06.03