Cell Proliferation during Morphogenesis of the Human Colon

Abstract

Cell proliferation during morphogenesis of human colon from 8 to 18 weeks of gestation was investigated using radioautography. The sites of [³H]-thymidine uptake were localized in the epithelium, the mesenchyme, and the muscularis externa. As long as the epithelium was stratified, the proliferative pool was very large, and the highest labeling indices (up to 28%) were found during this period. With the formation of villi, the proliferative pool decreased and focused exclusively in the developing crypts by 14–15 weeks. Between 8 and 11 weeks, the labeling index was similar both in the epithelium and the mesenchyme. By 13 weeks of gestation, the small intestinal cell proliferation pattern (epithelium > mesenchyme > muscular layer) was established in the fetal colon. The biochemical quantitation of the [³H]-thymidine uptake into the total colonic DNA supported the decreasing cell proliferation pattern determined by radioautography. The present investigation establishes basic quantitative data regarding cell proliferation during a particular developmental phase of the human colon.

Light microscopic autoradiographic study of DNA synthesis in cecal epithelial cells of aging mice.

“…We also found in this study that DNA synthesis in the lower half of the crypts was greater than in the superficial half of the crypts, and the same tendency has also been reported in small intestine (Leblond and Messier, 1958) and colon (Arsenault and MCnard, 1989;Minard and Arsenault, 1987;Eastwood and Trier, 1974;Chang and Leblond, 1971a.b) by [3H]-thymidine autoradiography. The observations suggested that renewal and replacement of mouse cecal epithelium continues from the fetal stage to senescence and that the cells of cecal epithelium were renewed continuously by production of new cells in the bases of the crypts to replace the numbers of superficial cells lost near the lumen (Chang, 1971;Leblond and Messier, 1958).…”

Insulin Modulates Cellular Proliferation in Developing Human Jejunum and Colon

“…The labeling indices were determined to establish whether insulin (3 mU/ml) affected the proliferation at the epithelial cell levels (table 1). The incorporation of the radioactive precursor occured mainly in the epithelium and to a lesser degree in the mesenchyme and muscular layers, as expected [23,24]. The labeling index was significantly higher in insulin-treated explants (p !…”

“…All results were expressed as disintegrations per minute per microgram of DNA. Selected tissues were fixed and embedded in Epon as previously described [23,24]. The sections (1 Ìm) were mounted on glass slides and stained with aldehyde fuchsin.…”

Morphological changes and cellular proliferation in mouse colon during fetal and postnatal development

“…~9 0 ; 170. firmed the confinement of proliferating cells in cell aggregates distributed over the mouse mucosal folds and that these aggregates are the precursors of the cryptlike invaginations already seen between 2 and 4 days after birth. In human fetal colon, which develops true villus structures, such distribution of proliferating cells was never seen, as [3Hl-thymidine labeled cells were always located in the developing crypts at the base of the villi (Arsenault and Menard, 1989). While the proliferative pool occupies the midcrypt portion in the proximal colon, it is mainly located at the base of the crypt in the distal colon.…”