Effects Of Restrain Stress And Pg-LPS On The Function Of Peritoneal Macrophages In Rats

Objective: To explore the effects of restrain stress and Pg-LPS on the change of NO,TNF-α,H₂O₂ and cytokines secretion from peritoneal macrophages in rats. To observe the effects of restrain stress and Pg-LPS on the apoptosis of peritoneal macrophages in rats.Methods: Part 1 Rats (SD, male) were tested by using restrain stress. Rats were divided into 2 experimental groups randomly (no stress, stress). Electronic animal scale was used to weigh the rats before and after stress conditions. After stress conditions, the rats were sacrificed, and their peritoneal macrophages were isolated, counted , cultured and purify. Cells were divided into 4 gropes: control, Pg-LPS stimulated, stress, stress+ Pg-LPS stimulated. Then the control and stress grope cells were cultured with RPMI-1640,the Pg-LPS stimulated and stress+ Pg-LPS stimulated grope cells were cultured with RPMI-1640+1μg/mlPg-LPS. After 24 hours, cell culture supematants were collected and assayed for NO, TNF-α,H₂O₂.Part 2 Rats (SD, male) were tested by using restrain stress. Rats were divided into 3 experimental groups randomly (no stress, one day stress, 12 days stress).After stress conditions, the rats were sacificed, and their peritoneal macrophages were isolated, cultured and purify. All the cells were then cultured with RPMI-1640+ 1μg/ml Pg-LPS. After 24 hours, cell culture supematants were collected and assayed for IL-Iβ,IL-2,IL-6,IL-10.Part 3 Rats (SD, male) were tested by using restrain stress. Rats were divided into 2 experimental groups randomly (no stress and stress).Afier stress conditions, the rats were sacrificed, and their peritoneal macrophages were isolated, cultured and purify. Cells were stimulated with 1μg/ml and 0.01μg/ml Pg- LPS. After 24 hours, cells were collected and observed with fluorescence staining and TUNEL. Results: The body mass in the stressed rats was significantly lower than that in the non-stress group (p＜0.05). The number of cells in the peritoneal cavity of stressed rats was significantly reduced in comparison to those from non-stressed animals (p＜0.05). The level of H₂O₂ was significant difference between the Pg-LPS stimulated and control cell group (p＜0.05). The level of H₂O₂ is suggested significant difference between the stress and control cell group(p<0.05 ). The level of NO, H₂O₂,TNF-αis suggested significant difference between the stress+ Pg-LPS stimulated and control cell group (p＜0.05).The level of cytokines was no significant difference between the one day stress and no stress group (p＞0.05). The level of IL-1β,IL-6 is suggested significant difference between the 12 days stress and no stress group (p＜0.05). The level of IL-2 is suggested significant difference between the 12 days stress and 1 day stress group (p＜0.05). The level of IL-10 is suggested no significant difference within groups (p＞0.05)The apoptosis rate of macrophages in the stress and no stress group increased after 1μg/ml Pg- LPS stimulate (p＜0.05). Compared with the no stress group, the apoptosis rate of macrophages in the stress group is significantly higher after 1μg/ml Pg-LPS stimulate (p＜0.05).Conclusion: (1) The results suggest that chronic restrain stress can lower the body mass of rats. Chronic restrain stress can reduce the number of macrophages in the peritoneal cavity in rats. Chronic restrain stress and Pg- LPS modulates NO,H₂O₂,TNF-αsecretion from macrophages. (2)After 1μg/mlPg- LPS stimulate,acute stress can't change the cytokines level,but chronic restrain stress modulates the level of IL- 1β,IL-6,IL-2. (3) 1μg/ml Pg- LPS induce apoptosis in macrophage. Restrain stress increases the apoptosis rate of 1μg/ml Pg- LPS stimulated macrophages.