STUDIES ON THE ABSORPTION OF VITAMIN B12
II. OBSERVATIONS IN THE JAPANESE GASTRECTOMIZED SUBJECTS
1962 年 8 巻 1 号 p. 57-67
詳細
1962 年 8 巻 1 号 p. 57-67
The intestinal absorption of orally administered Co60-B12 was studied in Japanese subjects having undergone gastrectomy by means of either fecal or urinary excretion test or hepatic uptake method. At the same time, in conformity of the reports that D-sorbitol is able to enhance B12 absorption in normal persons, the effect of the agent was investigated in gastrectomized subjects. Results obtained are as follows:
1. In extensive gastric resection such as total or subtotal gastrectomy, a strikingly defective B12 absorption was observed in all the cases tested by either method. The defect in B12 absorption was corrected by the addition of hog intrinsic factor, indicating that the lack of intrinsic factor is responsible for the defect. In partial gastrectomy, however, B12 absorption was found to be normal in all the cases but one. Thus the author was led to a conclusion that the more extensive the gastric resection, the more defective the B12 absorption in general.
2. As regards the enhancing effect of D-sorbitol, it was noted that the addition of the agent did correct the defective B12 absorption in subtotal gastrectomy, but did not in total gastrectomy. So it was concluded (a) that D-sorbitol had no intrinsic factor activity itself and (b) that the agent could enhance B12 absorption only when the resected stomach preserved the function of intrinsic factor secretion, no matter how little it may be.
3. Of interest was the B12 absorption in a case of subtotal gastrectomy; neither hog intrinsic factor nor D-sorbitol was effective for the enhancement of the B12 absorption, whereas tetracycline administration resulted in a marked improvement of the defective B12 absorption. Thus the defective absorption was demonstrated to be due solely to abnormal bacterial population in the intestine rather than to the lack of intrinsic factor.
4. In addition, some brief comments were made on the relation between B12 absorption and megaloblastic anemia following gastrectomy.
