Mechanisms of fat malassimilation following total gastrectomy in rats

The present study is designed to elucidate the mechanisms of fat malassimilation following total gastrectomy. Using male Wistar rats, total gastrectomy with an esophagoduodenostomy was performed. Totally gastrectomized and normal control rats, provided with intestinal lymph fistula or closed intestinal loops with intact blood supply, were used for the absorption studies. The lymphatic absorption of the emulsion in the totally gastrectomized rats, administered into the duodenum, was significantly less than that in the control, administered into the stomach or duodenum. Fat assimilation in the totally gastrectomized rats was obviously disturbed. In the totally gastrectomized rats, the lymphatic absorption of the micelle was significantly higher than that of the emulsion. An examination of the lipid absorption in the closed intestinal loops, injected micellar solution, showed no differences between the control and totally gastrectomized rats in the lumen or wall recovery, while, the total esterified lipids in the intestinal mucosa from the ligament of Treitz to the cecum of the totally gastrectomized rats were significantly less than those of the control. These results suggest that postgastrectomy fat malassimilation is due to both an impaired micellar formation and the disturbed resynthesis of triglyceride from absorbed fatty acid and monoglyceride.