Effect of Antagonists of Calcium and Phospholipase A on the Cytopathogenicity of Entamoeba histolytica

• Published in: The Journal of infectious diseases Vol. 152; no. 3; pp. 542 - 549
• Main Authors: Ravdin, Jonathan I., Murphy, Cheryl F., Guerrant, Richard L., Long-Krug, Sharon A.
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 01.09.1985; University of Chicago Press
• Subjects: Adhesiveness; Amibiasis; Animals; Biological and medical sciences; Calcium; Calcium - antagonists & inhibitors; Calcium - metabolism; Calcium Channel Blockers - pharmacology; Cell Line; Cell membranes; Cell Survival; Chemical suspensions; CHO cells; Cricetinae; Cytolysis; Dextrans; Edetic Acid - pharmacology; Entamoeba histolytica; Entamoeba histolytica - enzymology; Entamoeba histolytica - metabolism; Entamoeba histolytica - pathogenicity; Enzymes; Female; Fundamental and applied biological sciences. Psychology; Gallic Acid - analogs & derivatives; Gallic Acid - pharmacology; Human protozoal diseases; Hydrocortisone - pharmacology; Infectious diseases; Life cycle. Host-agent relationship. Pathogenesis; Medical sciences; Original Articles; Ovary; Parasitic diseases; Pharmacology; Phosphatidylcholines; Phosphatidylcholines - pharmacology; Phospholipases - metabolism; Phospholipases A - antagonists & inhibitors; Phospholipases A - metabolism; Protozoa; Protozoal diseases; Quinacrine - pharmacology; Stearates - pharmacology; T lymphocytes; Tropical medicine; Pathogenicity; Cytolysis; Protozoa; Antagonism; Trophozoite; Calcium; Enzyme; Entamoeba histolytica; Pathogen; Cell; Phospholipase A
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/152.3.542

The in vitro mechanisms by which Entamoeba histolytica trophozoites lyse target Chinese hamster ovary(CHO) cells were examined. Calcium chelators ethylenediaminetetraacetate and ethyleneglycol bis (β-aminoethyl ether)-N,N′-tetraacetate (10mM) inhibited amebic cytolysis of target CHO cells (P < .01). A putative antagonist of intracellular calcium flux, 8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate(TMB-8; ⩾250µM, inhibited amebic adherence and cytolysis (P <.001). Quinacrine, Rosenthal's inhibitor (dimethyl-dl-2,3-distearoyloxypropyl-2′-hydroxyethyl ammonium acetate), phosphatidylcholine, and hydrocortisone (⩾10− M), all pharmacological antagonists of eukaryotic phospholipase A enzymes, inhibited amebic killing of target CHO cells (P <.001). At 37 C quinacrine and hydrocortisone reduced amebic adherence to CHO cells, whereas Rosenthal's inhibitor and phosphatidylcholine did not. Phosphatidylcholine and TMB-8 demonstrated a synergistic inhibitory effect on amebic killing of target CHO cells(P < .001). These studies indicate that extracellular calcium ions, amebic intracellular calcium flux, and amebic phospholipase A activity are required for cytolysis of target cells by E. histolytica.