Influence of Administered Indigenous Microorganisms on Uptake of [Iodine-125] γ-Globulin In Vivo by Intestinal Segments of Neonatal Calves

Abstract

Ten calves less than 14h of age (average 8.6h) were anaesthetized, and the intestine was ligated into segments 10cm in length at 3-cm intervals beginning 1.8m anterior to the ileocecal junction and proceeding proximally. Seven treatments were assigned in random order to segments in three successive sections of the small intestine. Segments received 1ml of viable bacteria of intestinal origin, autoclaved bacteria of intestinal origin, or sterile microbiological broth at zero time; then after 4h they were injected with iodine-125 labeled γ-globulin. After an additional 1.5h, the experiment was ended and uptake assayed. Two treatments measured anaerobic microbial growth after 4h incubation with 1ml of either sterile broth or live bacteria culture. Residual [iodine-125] γ-globulin was measured in segments receiving 1ml of sterile broth or live bacteria culture with 5.5-h incubation followed by 15-s exposure to labeled γ-globulin. Uptake was lowest in segments receiving live bacteria as compared to segments receiving sterile inocula. Number of bacteria per gram of tissue was correlated negatively with uptake. Low corticosteroids in serum were associated with low uptake of γ-globulin.