Effects of gradient heat stress on phagocytosis of liver Kupffer cells in vitro / 解放军医学杂志

ABSTRACT

Objective To investigate the effect of gradient heat stress on phagocytosis of hepatic Kupffer cells (KCs) in vitro in rats. Methods Rat Kupffer cells were isolated in vitro and the temperature for gradient heat stress was set at 37, 39, 41 and 43℃. After thermal stimulation, cell injury was detected by PI and Hochest33342 staining. CCK-8 assay was used to investigate difference in cellular proliferation rate over 24h between the groups. Flow cytometry was used to investigate the influence of heat stress on the phagocytosis of KCs. Results Compared to the normal control group, cells in each heat stress group exhibited varying degrees of damage, especially cells in 43℃ group. The ratio of damage cells increased with the increase of heat stress severity (P<0.05). Proliferation assay indicated that the proliferation rate of cells in each heat stress group was significantly decreased in comparison with normal control group 6h after heat stress (P<0.05). After 12h recovery, decrease in proliferation rate was observed only in 43℃ group (P<0.001), and no difference in the rate of proliferation could be observed between the heat stress groups and normal control group after 24h recovery. Flow cytometry showed, that the phagocytosis of KCs decreased in heat stress groups compared with control group, especially in 43℃ group (P<0.05). This phenomenon disappeared after 24h recovery. Conclusion Heat stress can inhibit the phagocytosis of rat liver KCs through its cytotoxic effect on KCs, and subsequently inhibits its proliferative ability. Further investigation of the effect of heat stress on KCs may help understand the pathogenesis of heat stress.