Digestion and absorption rates of [3H]-oleic acid and [14C]-triolein do not differ in rats fed heated (-) and (+) gossypol cottonseed and soybean flours.

This study was conducted to compare in vivo the acute effects of heated (+) and (-) gossypol cottonseed flours with those of soybean flour on lipid digestion and absorption in growing rats. Rats were fed by gastric intubation mixed [3H]-oleic acid and [14C]-triolein with heated flours or without flour (control). Lipid digestion and absorption were determined for 6 h after meal intubation. Both radioactivities recovered in gastrointestinal tract were significantly higher in rats fed (+) gossypol cottonseed flour than in all other groups. The majority of both recovered radioactivities was found in stomach contents, then in stomach wall and finally in intestinal wall. The distribution of both radioactivities at different gastrointestinal levels was similar. In stomach contents and wall, [14C]-radioactivity was primarily in triacylglycerols, but was also recovered in free fatty acids and diacylglycerols. In intestinal wall (mucosa + tunica) [3H]-radioactivity was found at greatest levels in free fatty acids, then in triacylglycerols and diacylglycerols. Greatest [14C]-radioactivity was found in triacylglycerols, then in free fatty acids, in diacylglycerols and last in phospholipids in rats fed the three flours. Therefore no quantitative differences in lipid digestion and absorption were observed among the rats fed the three flours. In conclusion, both cottonseed flours slowed lipid digestion and absorption compared with soybean flour and this delay was greater in the rats fed (+) gossypol cottonseed flour than in those fed (-) gossypol cottonseed flour. However, this inhibiting effect was probably too low to induce physiologically important effects on lipid digestion or absorption.