scholarly journals The effects of corticosterone and cortisone on the uptake of polyvinyl pyrrolidone and the transmission of immunoglobulin G by the small intestine in young rats.

1976 ◽  
Vol 254 (2) ◽  
pp. 389-403 ◽  
Author(s):  
B Morris ◽  
R Morris
Keyword(s):  
Small Intestine ◽  
Immunoglobulin G ◽  
Polyvinyl Pyrrolidone ◽  
Young Rats

Nippostrongylus brasiliensis: the distribution of primary worm populations within the small intestine of neonatal rats

Parasitology ◽  
1974 ◽  
Vol 68 (3) ◽  
pp. 339-345 ◽  
Author(s):  
D. Conwil Jenkins
Keyword(s):  
Small Intestine ◽  
Primary Infection ◽  
Host Immunity ◽  
Nippostrongylus Brasiliensis ◽  
Neonatal Rats ◽  
Young Rats ◽  
Privileged Site ◽  
Day By Day

When neonatal rats were exposed to a small (200 larvae) primary infection of Nippostrongylus brasiliensis the worms that became established in the intestine were found in the mid-jejunum on both the seventh and the fourteenth day after infection. By day 21 most of the worms had migrated to the duodenum where they remained subsequently.When similar rats were exposed to a heavy primary infection (1500 larvae) the worms were found to be distributed along the length of the duodenum and jejunum by the seventh day. By day 28, however, a proportion of worms equal to that formerly located in the jejunum had been expelled, leaving a population of about 300 worms in the duodenum.It is suggested that the increased longevity of those worms that survive the effects of host immunity is dependent on their location at the duodenal site. The possibility is raised that the duodenum may be an immunologically privileged site for N. brasiliensis in young rats.

NEONATAL ADRENOCORTICAL FUNCTION AND ITS POSSIBLE RELATION TO THE UPTAKE OF MACROMOLECULES BY THE SMALL INTESTINE OF THE GUINEA-PIG AND RABBIT

1972 ◽  
Vol 55 (2) ◽  
pp. 397-404 ◽  
Author(s):  
K. W. MALINOWSKA ◽  
R. N. HARDY ◽  
P. W. NATHANIELSZ
Keyword(s):  
Small Intestine ◽  
Guinea Pig ◽  
Plasma Cortisol ◽  
Cortisol Concentration ◽  
Polyvinyl Pyrrolidone ◽  
Adrenocortical Function ◽  
Rabbit Plasma ◽  
High Concentration ◽  
Plasma Cortisol Concentration

SUMMARY Plasma cortisol and corticosterone were separated by Sephadex LH-20 chromatography. The high concentration of plasma cortisol immediately after birth in the guinea-pig coincided with the decline in 125I-labelled polyvinyl pyrrolidone (PVP) uptake (closure) between 48 and 72 h. Similarly, in the rabbit, plasma cortisol concentration was increasing at the time of closure, 18–21 days after birth. These results suggest that there is a correlation between the time when the concentration of the main plasma adrenocortical steroid rises and the time when the neonatal small intestine ceases to take up PVP.

scholarly journals Distribution of immunoglobulin G receptors in the small intestine of the young rat.

1980 ◽  
Vol 85 (1) ◽  
pp. 18-32 ◽  
Author(s):  
R Rodewald
Keyword(s):  
Small Intestine ◽  
Immunoglobulin G ◽  
Specific Binding ◽  
Proximal Jejunum ◽  
Luminal Surface ◽  
Surface Receptors ◽  
Receptor Complexes ◽  
Absorptive Cells ◽  
Igg Receptors ◽  
Old Rats

Conjugates of horseradish peroxidase (HRP) and immunoglobulin G (IgG) were used to map the distribution of cell surface receptors that can bind IgG at 0 degrees C within the small intestine of 10-12-d-old rats. Luminal receptors are present only within the duodenum and proximal jejunum. In these locations, receptors are limited to absorptive cells that line the upper portion of individual villi. Near villus tips, receptors are relatively evenly distributed over the entire luminal plasmalemma. In the midregion of villi, receptors are unevenly distributed over the luminal surface. Receptors (a) specifically bind rat and rabbit IgG, (b) recognize the Fc portion of the immunoglobulins, and (c) bind at pH 6.0 but not pH 7.4. To determine whether IgG receptors are confined to the luminal portion of the plasmalemma, intact epithelial cells were isolated from the proximal intestine of 10-12-d-old rats and incubated with HRP conjugates at 0 degree C. The specific binding of rat IgG-HRP to cells at pH 6.0 indicates that IgG receptors, which are functionally similar to those found on the luminal surface, are also present over the entire abluminal surface of absorptive cells. These results are consistent with the transport of IgG to the abluminal plasma membrane in the form of IgG-receptor complexes on the surface of vesicles. Exposure of these complexes to the serosal plasma, which is presumably at pH 7.4, would cause release of IgG from the receptors. To assess possible inward movement of vesicles from the abluminal surface after discharge of IgG, intravenously injected HRP was used as a space-filling tracer in the serosal plasma. HRP could be visualized within the coated and tubular vesicles responsible for transport of IgG in the opposite direction. These vesicles may, therefore, provide a pathway whereby receptors shuttle between the luminal and abluminal surfaces of cells.

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