X-Ray microanalysis of the secretory granules in goblet cells of mouse intestinal tracts: Changes with age

Abstract

Changes in the elements in goblet cell secretory granules in three portions of the intestinal tract — duodenum, proximal colon, and distal colon — in mice from 14 days to 18 months after birth were studied by quantitative electron probe X-ray microanalysis on quick-frozen and freeze-dried cryosections by calculating the ratio of each element. In the analysis of five elements, the peaks decreased in the order of sulfur (S), potassium (K), chlorine (Cl), phosphorus (P), and calcium (Ca) in the duodenum at 1 month; in the proximal colon, the peaks declined in the order of K, S, Cl, Ca, and P at 3 months; and in the distal colon, the peaks declined as S, K, Ca, Cl, and P at 3 months. The highest average ratio of S was obtained in the duodenum at 1 month, and this value then declined with age. In the proximal colon, the average ratio of K was the highest at 3 months, then declined afterward with age. The highest average ratio of S was at 3 months, and the highest average ratio of K was at 1 month in the distal colon. The ratio of peak counts to the background was calculated for each type of granule. Significant differences were found in the ratios of S and K between the proximal and distal colon. As for S, the duodenum and the distal colon had the highest ratios and the proximal colon had the second highest. Concerning K, the proximal colon had the highest and the duodenum and the distal colon the second highest ratio. The secretory granules of goblet cells in the three portions of the intestinal tract were shown to contain different amounts of each element. Especially, the amount of S differed most from the proximal to the distal colon.