Involvement of remnant spleen volume on the progression of steatohepatitis in diet-induced obese rats after a splenectomy.

AIM

This study investigated the correlation between remnant spleen volume after splenectomy (SPX) and the degree of hepatic steatosis and/or inflammation.

METHODS

Male Sprague-Dawley rats were fed HF food and divided into three groups: sham-operation (Sham) group, a hemisplenectomy (H-SPX) group, and a total-splenectomy (T-SPX) group. Serum was collected and livers removed 12 weeks after surgery. We measured serum lipid markers and evaluated liver changes by comparing the three groups. Additionally, we examined liver changes 24 weeks after SPX.

RESULTS

Serum triglyceride and free fatty acid levels after SPX were higher than those of sham controls, and a significant difference was found between T-SPX and the other groups (P < 0.05 for each). Increased intrahepatic fat accumulation was shown in SPX rats along with lower residual spleen volume; this fat accumulation after SPX was accelerated in rats at 24 weeks. Additionally, liver inflammatory changes, including an increase in the Kupffer cell population and pro-inflammatory cytokine production, as well as a high level of oxidative stress, were observed in the liver sections from SPX rats, which correlated significantly with less volume of the residual spleen. Also, an increase in pro-inflammatory cytokine content and a decrease in anti-inflammatory cytokine content were shown in the residual spleen from H-SPX rats, as compared to those of sham controls (P < 0.05 for each).

CONCLUSION

These results indicate the importance of preserving splenic tissue. This residual spleen may play an important role in preventing the progression from diet-induced hepatic steatosis to steatohepatitis.