Fig. 4
Surgery impaired gut barrier in aged but not young mice. A VISQUE® InVivo Smart-LF system was used to image the mice with FITC-dextran gavage treatment, no FITC-dextran gavage mice were used as control. The red area displays the fluorescence-positive area of FITC-dextran after enhancement. B Correlation with A, positive area of FITC-dextran in mice was calculated using ImageJ to indicate the permeability of the mouse intestine. C Mice were exposed to the abdominal colon before sacrifice and the colon was imaged using the mouse Doppler system. D Correlation with C, quantitative statistics of colonic blood flow in mice using the Moor FLPIR V40 program. E Levels of FITC-dextran in mouse serum were measured using a multifunctional fluorescence detector after 4 h of FITC-dextran gavage. F ELISA was used to detect the IL-6 level in the mouse serum in each group. G ELISA was used to detect the TNF-α level in the mouse serum in each group. H ELISA was used to detect the LPS level in the mouse serum in each group. I Representative images of the cecum and colon of each group of mice, with a straightedge indicating the length of the colon. J Correlation with I, the differences between the four groups of the length of colon were analyzed. K Immunofluorescence staining was used to detect the expression level of the tight junction protein ZO-1 (red) in the mouse colon tissues in each group. L Correlation with K, the fluorescence intensity of ZO-1 in the mouse colon tissues was calculated. M Immunohistochemical staining was used to detect the expression level of IL-17a and IL-22 in the mouse ileum tissues in each group. N Correlation with M, the mean IOD/area of IL-17a in ileum was calculated. O Correlation with M, the mean IOD/area of IL-22 in ileum was calculated. P Immunofluorescence staining was used to detects the expression level of the tight junction protein ZO-1 (red) in the mouse ileum tissues in each group. Q Correlation with P, the fluorescence intensity of ZO-1 in the mouse ileum tissues was calculated. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001, ns means no significant