The effects of prostaglandins on the secretion resulting from Entamoeba histolytica "enterotoxin"
Leitch, G.J.; Udezulu, I.A.
Archivos de Investigacion Medica 13(Suppl): 105-108
1982
ISSN/ISBN: 0066-6769 PMID: 6295300 Document Number: 182853
Exposure of in vivo rat colon loops to extracts of 106 E. histolytica HM-1 trophozoites/ml resulted in secretion during the 1 h period of extract exposure, and for the 3 subsequent hours when the loops were exposed to saline. This secretion only occurred when the animals were administered 0.1 mg/kg indomethacin. This requirement for indomethacin suggested that prostaglandin-mediated mucosal cytoprotection had to first be reduced before an amoeba "enterotoxin" could induce intestinal secretion. To test this hypothesis, an exogenous prostaglandin was administered in an attempt to reinstate cytoprotection and inhibit amoeba extract-induced secretion. The short lived, antisecretory prostaglandin, prostacyclin (PGI2), was administered before and during, or after the period of exposure of the colonic loop to extract. This prostaglandin directly reduced the secretion during the period of its administration, and in some cases when administered with amoeba extract the PGI2 eliminated secretion entirely for the 4 h of the experiment. These data are interpreted as indicating that a prostaglandin-induced mechanism afforded the mucosa protection against "enterotoxin" elaborated by E. histolytica HM-1 strain. [AS].