Long-Term Protective Effects and Mechanisms of Gastric Bypass Surgery on the Kidneys in Hypertensive Obese Rat

Objective: Investigate the long-term protective effects of gastric bypass surgery on the kidneys of hypertensive obese rats to better understand the role of gastric bypass surgery in preventing renal injury in humans with hypertension and obesity.

Methods: Compare 6-week-old spontaneously hypertensive rats, including 30 Roux-en-Y gastric bypass (RYGB) and 30 sham operations. Body weight and blood pressure were monitored before and up to 12 months after the operation. Blood lipids, blood creatinine, and blood urea nitrogen were measured. Kidney pathology was assessed using HE staining, while renal fibrosis was observed via Masson staining. Inflammatory indicators were examined by ELISA. The expression of the NLRP3 gene in the kidney was measured using immunofluorescence and western blot, and the changes in key pathways including ASC/IL-1β protein were verified.

Results: RYGB reduced the body weight of hypertensive obese rats and had a protective effect on blood pressure. Additionally, the bypass effectively mitigated renal inflammation and fibrosis. Moreover, RYGB modulated the expression of NLRP3 and prevented kidney damage via the ASC/IL-1 pathway.

Conclusion: This study validates that RYGB effectively attains sustained blood pressure control in hypertensive obese rats and has a potential kidney-protective mechanism via the NLRP3-ASC/IL-1β pathway.