Vagotomy and antrectomy impairs canine fat absorption from solid but not liquid dietary sources

Abstract

Mild steatorrhea is common after all ulcer operations except parietal cell vagotomy. As these operations impair the grinding and sieving of solid food, we sought to determine the effect of vagotomy and antrectomy on fat absorption from solid (e.g., liver) as compared with liquid (e.g., margarine) dietary sources in the proximal small intestine. Midgut fistulas were placed in 13 dogs; 7 were controls and 6 underwent concurrent vagotomy and antrectomy. To label solid fat, the livers of live chickens were labeled with intravenous [14C]triolein and [3H]glycerol triether, an absorbable and nonabsorbable fat label, respectively. For the liquid fat label, these markers were mixed with margarine. A standard meal of steak, liver, bread, margarine, and water, with either the liver or margarine fat labeled, was fed and the midgut effluent was sieved and centrifuged to obtain four phases: large particles (> 0.5 mm), small particles (< 0.5 mm), aqueous, and oil, which were extracted and counted for 14C and 3H. The ratio of 14C to 3H in each fraction was used to determine how much fat was absorbed from each phase of chyme. With liver fat labeled, 48.3% ± 8.1% of the [3H]glycerol triether remained in large particles after vagotomy and antrectomy compared with 3.1% ± 1.0% in controls at midintestine (p < 0.001). After vagotomy and antrectomy, more than half of the liver fat (solid fat) was malabsorbed (57.1% ± 6.5% vs. 23.1% ± 6.6% malabsorbed, p < 0.01, vagotomy and antrectomy vs. controls), whereas fat absorption from margarine (liquid fat) was not reduced compared with controls (8.8% ± 2.5% vs. 13.6% ± 5.5% malabsorbed, p > 0.05, vagotomy and antrectomy vs. controls). These observations indicate that by reducing gastric trituration and releasing large particles of poorly digested food into the intestine, vagotomy and antrectomy impairs the absorption of fat selectively from solid, but not from liquid, dietary sources.