Structural changes in the small intestine associated with the uptake of polyvinyl pyrrolidone by the young ferret, rabbit, guinea‐pig, cat and chicken

Abstract

SUMMARY1. The entry of [1wI]polyvinyl pyrrolidone (PVP) of mean mol. wt. 160,000 (K. 60) into the epithelial cells of the small intestine has been measured in new-born animals of five species.2. The distribution along the intestine of cells capable of taking up[125I]PVP and the decrease and eventual cessation of uptake (closure) with increasing age have been investigated, and have been related to changes in the histological appearance of the small intestine. 3. The small intestine of the ferret took up PVP readily until 33-34 days after birth. From 34 to 37 days of age PVP uptake declined sharply and disappeared completely by 40-45 days. 4. In the ferret, unlike other species studied, some PVP was taken up by the duodenum. This continued for the first 4 weeks after birth. Thereafter PVP uptake gradually became confined to the terminal ileum.5. In the guinea-pig, PVP uptake was limited to the first 48 hr after birth. During this period the site of uptake was progressively restricted to the terminal ileum.6. In the rabbit, PVP could be taken up in the distal two-thirds of the 10. In the young guinea-pig, large PAS-positive granules were seen in the macrophages of the lamina propria. These appeared to migrate through the epithelium into the intestinal lumen. The significance of this finding and its relation to macromolecular uptake remain unclear.

The Mammary Gland in Mucosal and Regional Immunity

“…The exact mechanism leading to gut closure is unknown, although maturation of the lysosomal system is suspected because after closure in piglets only IgG fragments are found in blood Kraehenbuhl and Campiche, 1969). This was shown using polyvinylpyrrolidone in a number of species (Clarke and Hardy, 1970). Gut closure may be progesterone-associated because it parallels tight junction closure in the mammary epithelium (Nguyen et al, 2001).…”

Amniotic IGF-I supplements improve gut growth but reduce circulating IGF-I in growth-restricted fetal sheep

“…Embolization reduced gut weight and wall thickness and resulted in persistence of the apical endocytic complex (AEC), an extensive endocytic transport system capable of transporting large-molecular-weight molecules (16). In fetal sheep, the AEC has usually completely disappeared, apart from a few remaining vacuoles in the villus tip Values are means Ϯ SE.…”

Chemical and amino acid composition of colostrum and mature milk differ only slightly in mink (Mustela vison)

“…Furthermore, in the Marten family (Mustelidae), the uptake of macromolecules persists for several weeks after birth. Clarke and Hardy (1970) have demonstrated that uptake of polyvinyl pyrrolidone into the enterocytes of the small intestine is still active in 6‐week‐old ferrets kits, and mink kits are able to transport bovine serum albumin (BSA) up to the age of 5 weeks (J. Elnif, unpublished results). Thus, colostrum seems to be of little importance in conferring passive immunity and hence for kit survival in the mink.…”