Variation in crypt size and its influence on the analysis of epithelial cell proliferation in the intestinal crypt

Abstract

The standard model of epithelial cell renewal in the intestine proposes a gradual transition between the region of the crypt containing actively proliferating cells and that containing solely terminally differentiating cells (Cairnie, Lamerton and Steel, 1965 a, b). The experimental justification for this conclusion was the gradual decrease towards the crypt top of the measured labeling and mitotic indices. Recently, however, we have proposed that intestinal crypts normally undergo a replicative cycle so that at any time in any region of the intestine, crypts will be found to have a wide range of sizes. We show here that if this intrinsic size variation is taken into account, then a sharp transition between the proliferative and nonproliferative compartments of individual intestinal crypts is consistent with the labeling and mitotic index distributions of mouse and rat jejunal crypts. Thus there is no need to invoke the region of gradual transition from proliferating to nonproliferating cells as is done in the standard model. The position of this sharp transition is estimated for both the mouse and rat. Experiments to further test our model are suggested and the significance of the results discussed.

Effects of feeding fat‐coated butyrate on mucosal morphology and function in the small intestine of the pig

“…The evaluation of the mitotic compartment in the crypts did not reveal differences in the mitotic activity between feeding groups. The formation of new villi, however, is dependent on an increase of the mitotic activity, which leads to the formation of new crypts by crypt fission (Totafurno et al., 1988) and thus the enlargement of plicae. Only the number of villi can be counted directly, whereas the number of crypts that serve a single villus is variable.…”

Gastrointestinal cell proliferation and crypt fission are separate but complementary means of increasing tissue mass following infusion of epidermal growth factor in rats

“…23 The finding that colonic crypt volume was high when the number of branched crypts seen was low suggests that crypt volume may not be the only factor involved.…”

Comparison of polyglycolic acid, polycaprolactone, and collagen as scaffolds for the production of tissue engineered intestine

“…The organoids in this size range have a well-preserved architecture and contain the highest numbers of intestinal stem cells. [6] The average size of organoids varies with species, [40], and the scaffolds prepared and tested in this study used organoids isolated from 1-3 day rat pups. PGA consists of randomly entangled fibers providing a natural porous structure.…”