Diacylglycerol breakdown in plasma membrane of rat intestinal epithelial cells. Effect of E. coli heat-stable toxin.
Rat intestinal epithelial cells were isolated and the activity of the enzyme diacyglycerol lipase (DG lipase, EC 3.1.1.3) was investigated. When cells were treated with Escherichia coli heat-stable toxin (ST) liberation of endogenous glycerol and fatty acids was observed. The enzyme responsible for this effect could be demonstrated to be a DG lipase by using specific substrates. It was found that the activity of DG lipase was increased 5-6-fold with the substrates diolein and 1,2-dioleyl-rac-glycerol and triolein being neutral lipid insensitive to DG lipase. ST had no direct effect on the DG lipase. The enzyme DG lipase was activated via a chain reaction due to the hydrolysis of phosphatidylinositol (PI) by the enzyme PI-specific phospholipase C stimulated by ST.
Banik
N D
ND
Ganguly
U
U
D000818:Animals; D001095:Arachidonic Acids / Q000096:biosynthesis; D001427:Bacterial Toxins / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002855:Chromatography, Thin Layer; D004075:Diglycerides / Q000378:metabolism*; D004768:Enterotoxins / Q000494:pharmacology*; D029968:Escherichia coli Proteins; D005989:Glycerides / Q000378:metabolism*; D005990:Glycerol / Q000378:metabolism; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism*; D008071:Lipoprotein Lipase / Q000378:metabolism; D008297:Male; D008861:Microsomes / Q000378:metabolism; D051381:Rats
D001095:Arachidonic Acids; D001427:Bacterial Toxins; D004075:Diglycerides; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D005989:Glycerides; C034151:heat stable toxin (E coli); D008071:Lipoprotein Lipase; D005990:Glycerol