Duodenojejunal Bypass Plus Sleeve Gastrectomy Reduces Infiltration of Macrophages and Secretion of TNF-α in the Visceral White Adipose Tissue of Goto-Kakizaki Rats.

BACKGROUND: Current studies indicate that inflammation of white adipose tissue (WAT) is a pathogenic characteristic of insulin resistance. However, the significance of visceral WAT inflammation after bariatric surgery remains unclear.

METHODS: Duodenojejunal bypass plus sleeve gastrectomy (DJB-SG) was performed on Goto-Kakisaki rats. Weight, fasting blood glucose (FBG), and homeostatic model assessment of insulin resistance (HOMA-IR) in the DJB-SG group were compared to those in a sham surgery (SHAM) group every 2 weeks. The results of an oral glucose tolerance test (OGTT) and the volume of visceral adipose tissue (Visc.Fat) were compared before and 8 weeks postsurgery. Eight weeks after surgery, the rats were sacrificed and visceral WAT collected from the greater omentum. Tumor necrosis factor-α (TNF-α) and cluster of differentiation 68 (CD68) expression in the WAT were evaluated in paraffin-embedded sections by immunohistochemistry.

RESULTS: Compared with the SHAM group, the DJB-SG group demonstrated a significant reduction in weight, FBG, and HOMA-IR (P < 0.05), with elevation of insulin levels (P < 0.05) from 4 weeks after surgery. OGTT and the quantity of Visc.Fat were significantly reduced (P < 0.05) 8 weeks after surgery. Moreover, the expression of TNF-α and CD68 in the visceral white adipose tissue was significantly lower 8 weeks after surgery (P < 0.05).

CONCLUSIONS: The DJB-SG model established in Goto-Kakisaki rats achieved anticipated efficacy. Reduced TNF-α-related inflammation in visceral WAT may result in improved insulin resistance.