The occurrence of macrophage-like cholera toxin uptake cells in the intestinal villi of suckling rats.
An oral administration of cholera toxin (CT. 10m g) caused diarrhea in infant rats ranging in age from 1 to 14 days. After administration of the toxin a time sequence study was carried out using highly sensitive immunohistochemical procedures. CT was exclusively incorporated into a type of macrophage-like (ML) phagocytic cell. These cells were identified within the intestinal epithelium of rats suffering choleraic diarrhea. After 2 hrs cells taking up the toxin markedly increased in number and were found in both the mucosa and the lamina propria mucosae. After 4 hrs a small number of ML cells containing CT were still present in the mucosal epithelium, but were no longer observed in the lamina propria. Two kinds of monoclonal antibodies against rat macrophages were used to gain a clue as to the cytological characteristics of ML cells. ED1- or ED2-positive macrophages were demonstrable in the lamina propria and submucosa of the small intestines from control rats. In CT-treated rats a considerable number of cells positive for CT and ED1, or CT and ED2 antisera, were found within the epithelial cell layer and the lamina propria of intestinal villi. It is suggested that many ML cells responsive to CT, if not all, are ED1 and ED2 macrophages and are resident in the villous lamina propria where they can migrate to uptake CT in the intestinal lumen. CT B-subunit and heat-labile toxin (LT) B'-subunit from a mutant strain Escherichia coli were given to the rats in order to know the onset mechanism of toxin uptake. It seems likely that the toxin receptor, GM1 ganglioside, participates in the initiation of CT-uptake mechanism. A possible role of the intestinal ML cells was discussed.
Shimodori
S
S
Department of Medical Technology, Kyushu University, School of Health Sciences, Fukuoka, Japan.
Nada
O
O
Sakamoto
N
N
Hirose
R
R
Kawana
T
T
D000818:Animals; D000833:Animals, Suckling / Q000276:immunology*; D002772:Cholera Toxin / Q000276:immunology*; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000166:cytology* / Q000276:immunology*; D007583:Jejunum / Q000276:immunology; D008264:Macrophages / Q000276:immunology*; D008297:Male; D010587:Phagocytosis / Q000276:immunology; D051381:Rats; D017208:Rats, Wistar
D002772:Cholera Toxin