Absorption of Vitamin B12 from the Cecum of the Hen.

Abstract

It has been observed in this laboratory( 1 ) , in agreement with published data (2,3), that the vit. B12 in the contents of the ceca of the hen amounts to 6-7 pg per g dry matter. These comparatively high BIZ values are found in the ceca even though the bird is maintained on a B12 deficient diet. The further observation, that long periods of time are required to deplete a hen of B12 when fed a corn-soybean meal type diet, indicates possible absorption of the vitamin from the ceca. This problem was studied by determining; (1) the effect of cecectomy on the rate of depletion of B12 in the egg, and ( 2 ) the absorption of CO-60 labeled vit. B12 from the occluded cecum. For purposes of comparison the absorption of S-35 labeled methionine and sodium sulfate from the cecum was studied under the same conditions.Afethods. Rhode Island Red hens were used in these studies. One group of hens was cecectomized. Following the operation, these birds and a control group were maintained on a vit. B12 deficient diet(4). The rate of depletion of the vitamin in these birds was followed by estimation of the Blz activity of their eggs with Lactobacillus leichmannii( 5) using cyanide in the extraction procedure. The hens used in the second phase of this study were taken off feed approximately 18 hours prior to injection of the radioactive ma-*This project was supported in part by the U. S. Atomic Energy Commission.---terial. Cecal occlusion was accomplished by inserting a small glass rod (15 mm long) through the cloaca into the rectum, the lower intestine being pushed out through a lateral abdominal incision so that the rod could be directed into the cecum. The glass obstruction was then fixed in place in the cecum near the junction of the intestine by loose ties. Following this, the dose was injected into the lumen of the exposed cecum. Two different doses of co-60 labeled vit. B12 were used, one contained 15 pg with an activity of about 0.6 pc, and the other 4 pg with an activity of about 0.9 pc. Solutions containing 0.75 mg of methionine with an activity of approximately 12 JAC or 1 mg of sodium sulfate with an activity of 15 pc were injected. Blood samples were taken by heart puncture. The birds were sacrificed at 24 or 48 hours after injection and the various organs and tissues removed for analysis. In a few instances the kidneys were extracted with pH 4.5 acetate buffer in the presence of cyanide and aliquots taken for chromatography. The solvent system used consisted of acetone containing water ( 5 % VyV) and HC1 (8% V/V) (6). The chromatograms were developed against "no screen" X-ray film for a period of one month. Using this system B12 had an Rf of 0.03 and inorganic cobalt 0.84. Aliquots of the kidney extracts and all other samples, after the addition of cobalt or sulfate carrier were subjected to a complete ash procedure at Karolinska Institutets Universitetsbibliotek on July 12, 2015 ebm.sagepub.com Downloaded from

In Vitro Antibiotic Activity on Cecal Anaerobes with Emphasis on Uric Acid-Utilizing Bacteria

“…However, little evidence exists for direct cecal absorption of bacterial metabolites (Shrimpton, 1966;Jackson et al, 1955;Jayne Williams and Fuller, 1971). Total counts of cecal organisms on the order of 10 10 /g have been reported (Shrimpton, 1966;Salanitro et al, 1974b) with a large number of these anaerobic bacteria able to decompose uric acid (Barnes and Impey, 1974;Mead and Adams, 1975).…”