1. Isolation of a self-emptying sac of rat small intestine in vivo halved the cell production rate in the crypts of Lieberkühn as measured by colchicine blockade. 2. Starvation for 48 h of rats with isolated intestinal sacs caused a further halving of cell production rate in the sac. 3. Infusion of distilled water into isolated intestinal sacs for 72 h caused a similar degree of stimulation of ...

Short-circuit current and transepithelial potential difference were measured in toad hemibladders mounted as sacs on glass cannulae. When sac volume was changed by adding or removing fluid, short circuit current responded by increasing or decreasing during the ensuing half-hour. The time course of the response and its magnitude indicated that it was not artefactual. Furthermore, net sodium flux...

The ejection of internal organs, i.e., evisceration, is a well-known phenomenon in sea-cucumbers. We report the ability of a member of the Chordate phyla, the tropical ascidian Polycarpa mytiligera, to eviscerate and regenerate its gut within 12 days, and to rebuild its branchial sac within 19 days. Evisceration occurred within 4-43 seconds of gentle mechanical pressure exerted on the tunic in ...

I . The structure, renewal, embryonic development, and regeneration of the swimming setae of Daphnia carinata are described. 2. Each seta is formed by four giant cells, two (the core cells) forming the distal segment, and two (the sheath cells) the proximal segment. The inner ends of these cells extend back, as the seta strand, through the whole length of the rami of the antenna to be inserted ...

Classical descriptions of gut development specify subdivision into foregut, midgut, and hindgut together with their derivatives. This is based on the anatomical localisation of the anterior and posterior intestinal portals separating the roof of the yolk sac from the foregut and hindgut diverticulae. When considering the molecular basis of intestinal differentiation, it is necessary to think in...

The objectives of this study were to evaluate healing of experimentally severed superficial digital flexor tendons of the canine hind limb repaired by apposition using a Kessler pattern with no augmentation, or augmentation with an everted autologous venous graft or non-everted autologous venous graft. A total of 30 healthy, orthopaedically and neurologically sound mongrel dogs were used in thi...

MAWS, JAMES G., AND DAVID SCHACHTER. Active transptm of iron by intestine: efects uf oral iron and pregnancy. Am. J. Physiol. 203(1) : 81-86. 1962. -The active transport of iron has been studied further with everted gut sacs and loops of duodenum in the rat. The two-step absorptive mechanism appears to be one of the cellular processes which regulates iron absorption. A single dose of iron by mo...

MANIS, JAMES. Intestinal iron-transport defect in the mouse with sex-linked anemia. Am. J. Physiol. 220(l) : 135-139. 1971.-Everted duodenal gut sacs prepared from mice with sex-linked anemia (sZa) have a defect in the serosal transfer step of the active transport mechanism for iron that prevents the establishment of concentration gradients across the intestine greater than 1.0. The defect is p...