[Effects of two types of diet on plasma lipids in rats submitted to splenic surgery].

OBJECTIVE

The objective was to verify the effect of total splenectomy and ligature of the splenic vessels on the plasma lipid levels in rats fed a control diet or a diet supplemented with 2.5% cholesterol.

METHODS

Ninety-nine male Wistar rats weighting between 273 and 427 g (arithmetic mean: 349.46 +/-35.54) were randomly divided into four groups: group 1- control (N=19), nonoperated; group 2 - sham (N=19), laparotomy with spleen manipulation; group 3 -TS (N=31), total splenectomy; group 4 (N=30) simultaneous ligature of the splenic artery and vein. Blood was collected from all animals for determination of plasma lipids at the beginning of the experiment. Rats were than divided into two subgroups receiving either control diet (subgroup A) or diet supplemented with 2.5% cholesterol (subgroup B). Another blood sample was collected 90 days later for a new determination.

RESULTS

No significant difference in plasma lipids between the four groups was observed at the beginning (p>0.05). In subgroups 1A, 2A and 4A, there was no significant difference in the values of HDL, VLDL and triglycerides, except LDL that dropped significantly in subgroup 1A and 2A (p<0.05) and not significantly in subgroup 4A. In subgroup 1B, 2B and 4B there was a significant increase in late postoperative plasma total cholesterol, LDL, VLDL (p<0.05) and a not significant increase of HDL. In total splenectomy, at late postoperative there was a significant increase of cholesterol, LDL, VLDL and triglycerides, especially in subgroup B. In group 3 the cholesterol, LDL and triglycerides were more significant than in groups 1, 2 and 4.

CONCLUSION

Total splenectomy caused a more significant increase of cholesterol, LDL, VLDL and triglycerides in rats fed a cholesterol diet. The simultaneous ligature of vein and artery prevented alterations in plasma lipids observed in rats submitted to total splenectomy and maintained lipid levels similar to those of the control and sham groups.