g(m1)-ganglioside and ferric-chloride

Secretory diarrhea caused by cholera toxin (CT) is initiated by binding of CT's B subunit (CTB) to GM1-ganglioside on the surface of intestinal cells. Lactoferrin, a breast milk glycoprotein, has shown protective effect against several enteropathogens. The aims of this study were to determine the effect of bovine-lactoferrin (bLF) on CT-induced intestinal fluid accumulation in mice, and the interaction between bLF and CT/CTB with the GM1-ganglioside receptor. Fluid accumulation induced by CT was evaluated in the mouse ileal loop model using 56 BALB/c mice, with and without bLF added before, after or at the same time of CT administration. The effect of bLF in the interaction of CT and CTB with GM1-ganglioside was evaluated by a GM1-enzyme-linked immunosorbent assay. bLF decreased CT-induced fluid accumulation in the ileal loop of mice. The greatest effect was when bLF was added before CT (median, 0.066 vs. 0.166 g/cm, with and without bLF respectively, p<0.01). We conclude that bLF decreases binding of CT and CTB to GM1-ganglioside, suggesting that bLF suppresses CT-induced fluid accumulation by blocking the binding of CTB to GM1-ganglioside. bLF may be effective as adjunctive therapy for treatment of cholera diarrhea.

Topics: Animals; Cattle; Chlorides; Cholera Toxin; Dose-Response Relationship, Drug; Enterotoxins; Escherichia coli; Female; Ferric Compounds; G(M1) Ganglioside; Gangliosides; Intestinal Mucosa; Intestines; Lactoferrin; Mice; Protein Binding; Receptors, Cell Surface

Ferric ion-ferrocyanide staining and safranin-0-counterstaining of neocortical tissue from cats with GM1 gangliosidosis have established that pyramidal neuron meganeurites occur proximal to axonal initial segments and that they are distinct from axonal spheroids. The latter, which were found to be widely distributed throughout cerebral cortex, were located distal to axonal initial segments and could be differentiated from meganeurites at both light and electron microscopic levels. This report confirms an earlier electron microscopic study which suggested that meganeurites are of axon hillock origin, and illustrates the striking distinction between abnormalities in the soma-dendritic and axonal domains of neurons in a lysosomal storage disease.

Topics: Animals; Axons; Cats; Cerebral Cortex; Chlorides; Dendrites; Ferric Compounds; Ferrocyanides; G(M1) Ganglioside; Gangliosidoses; Microscopy, Electron; Neurons; Phenazines; Staining and Labeling