| ObjectivesTo observe the intestinal mucosal pathological damage and changes in the number and distribution law of lymphocytes in rat when the ambient temperature has a sudden change, explore the law of changes resulted from ambient temperature changes in intestinal mucosal immunization barrier, and then provide new ideas and morphological evidences for the protection of the immunization barrier in intestinal mucosa and the prophylaxis and treatment of enterogenous infection.Methods84 male rats at the age of 9～15 weeks were randomized into four groups, normal temperature (20℃), sudden drop in temperature to 4℃, sudden drop in temperature to -12℃and sudden rise in temperature to 37℃.21 rats were assigned for each group, and seven time points, 1h,4h,8h,12h,24h,48h and 168h, were observed for each group, three rats for each time point. The animals were put to death at each time point, respectively. Segments of duodenum, jejunum and ileum were fixed for 24h with 4% paraformaldehyde solution, and embedded with paraffin wax and sliced into sections. Mouse anti-rat CD4+, mouse anti-rat CD8+ and goat anti-tat CD20+ monoclonal antibodies were used to adjacent sections. CD4+ T-cells CD8+ T-cells and CD20+ B-cells were displayed by immunohistochemistry, respectively, and the number density by volume (Nv) of T-cell subgroups and that of B-cells were measured with square grid network measure system. The difference between each two intestines, that between epithelium layer and lamina propria layer and that between different ambient temperatures groups were compared by SPSS 16.0. In addition, intestinal mucosal histopathology was to be observed by routine HE stain.ResultsIntestinal mucosal lesion occurred to varying degrees in low temperature and high temperature groups, with degeneration and necrosis of epithelial cells, villi and membranae propria being off, capillarectasia and inflammatory cell infiltration in lamina propria, which was most serious in the 37℃group. The time point for serious lesion varied in different groups, with the lesion being most serious at 8h in the 37℃group and most significant at 12h in the 4℃and-12℃groups. Mucosal restoration to various degrees, but not to normal level, was observed in three small intestines. The duodenum had most serious lesion in three intestines, followed by the jejunum, and then the ileum. Only CD8+ T-cells could be observed in intestinal mucosal epithelium CD4+ T-cells and CD8+ T-cells and CD20+ B-cells observed in intestinal mucosal lamina propria in the normal temperature group. The number density by volume (Nv) of CD8+ T-cells in epithelium and CD4+ T-cells and CD8+ T-cells CD8+ T-cells in lamina propria was highest in duodenum, followed by jejunum and then ileum.Nv of CD8+ T-cells in epithelium and CD4+ T-cells and CD8+ T-cells in lamina propria in each intestine was lower at each time point in the 37℃group than the normal temperature group, the value of CD4+/CD8+ T-cells decreased and Nv of CD20+ B-cells in lamina propria higher.Nv of CD8+ T-cells in epithelium and CD4+ T-cells and CD8+ T-cells in lamina propria in each intestine were lower at each time point in the 4℃and -12℃groups than the normal temperature group, the value of CD4+/CD8+ T-cells decreased and that of CD20+ B-cells in lamina propria higher. Nv of CD8+ T-cells in lamina propria was lower in the -12℃group than in the 4℃group, and Nv of CD4+ T-cells, CD8+ T-cells and B-cells in lamina propria was lower in the -12℃group than in the 4℃group.Various ambient temperature changes had effects to different degrees on various lymphocytes. CD4+ T-cells decreased when suffered low or high temperatures, with the outcome in high temperature more significant. CD8+ T-cells decreased when suffered low or high temperatures, but the outcome of high temperatureis more significant.CD20+ B-cells increased when suffered low or high temperatures, with the outcome most significant in the 4℃group.Conclusion1. Both sudden drop and rise in ambient temperature can result in lesion in small intestinal mucosal mechanical barrier, with pathology of degeneration and necrosis of epithelial cells, villi and membranae propria being off, capillary dilatation and congestion, central lacteal dilatation and inflammatory cell infiltration.2. Both sudden drop and rise in ambient temperature can influence the small intestinal mucosai immunization barrier, with manifestation of cellular immunosuppression such as decreased CD4+ and CD8+ T-cells and decreased value of CD4+/CD8+ T-cells, of humoral immunopotentiation such as increased CD20+ B-cells.3. The lesion of small intestinal mucosal mechanical barrier resulted from sudden rise in ambient temperature is more serious, while both sudden drop and rise in ambient temperature can influence the immunization barrier in the small intestinal mucosal of rats. |
PDF Full Text Request